We have some 3" (of useable space) in our current old kitchen and its fine for a lot of silverware, and kitchen utensils. I think 3.5 would be ideal next to stove and for silverware.

My kitchen is 95% drawers, exceptions are trash pullout, under the sink, and one other pullout. When I measured the drawers to assess the width, I measured from the bottom of the drawer box to the top of the rail. My shallowest drawer is 3 7/8", I find it very functional. It allows for a 1 cup Pyrex measuring cup to be stored upright, which makes me very happy with my baking tools drawer. Still working the kinks out in the organization of some of my drawers- LOL- that could be a life long tweaking process as I am pretty fussy.

We have mostly all drawers and will never go back.
Our shallowest are 3.5 inches. We have two, one is our charging drawer for cell phones/tablet/Nook. The other one is our "junk" drawer, and we used inserts to organize pens, pads of papers, spare keys, twist ties, tape, etc.

One of my favorite drawers are the 5 inches, which are perfect for our ziploc containers. No more crouching and reaching blindly into a giant stacked mess of a cupboard.

Kitchen cabinets are designed as a system to have the horizontal lines formed by the drawers be contiguous around the room, and then integrate fully into the heights of the tall and wall cabinets. While you can do a drawer stack with multiple 2" drawers here and do the next one with all 6" drawers, it create visual disharmony and dissonance unless you use divisions that will create some similar horizontal lines. All drawers is not all about function, even though it's the most functional choice. If you don't have any uppers planned, you also need a large walk in pantry. The most ergonomic storage in any kitchen is in the range from your knees to about 6" over your head. With no uppers, you give up a lot of that space range and that needs to be made up for with auxiliary storage elsewhere.

Totally agree with GreenDesigns. I wouldn't have all drawers if I didn't also have a walk in pantry to store my jars of tomatoes, dried beans,etc. And, you do have to consider the alignment of the drawer depths and those visual lines they create.

We will have a good-sized pantry. We also use an antique Hoosier cabinet for storage. My vertically-challenged wife rarely uses the upper cabs in our current small kitchen. The new kitchen will have about 3 times the cabinet/counter space that our current one has, so I don't think we'll miss the uppers. I'm also planning some shallow open shelves for everyday glasses and mugs.

That's a good point about the drawers lining up. I'll really have to think about how many shallow drawers I can actually use. Does it help if you have something different in the corner to break up the continuity? In one corner there will be an angled prep counter with no cabinet under it so you can sit while doing prep work. Would it still be objectionable if the adjacent drawers didn't line up?

I have some Norcroft drawer bases. While I love them, their about 2 7/8" deep top drawers are too shallow. If I could make them 1" deeper, they'd be a lot more functional for me.

I wouldn't trade any of my drawers, though, for anything. I've just retrofitted the credenza I'm building with drawers. I'd built it for reach-in shelves under it and recently realized how stupid that was. I hate reach-ins! So... drawers it is! Deep drawers.

When lining the lines up you can have multiple shallow drawers next to a deeper one as long as they cover the same amount of space. So the lines line up. For example if you have 2 shallower next to 1 deep you'll make sure the top of the deep one line up with the top of the 1st shallow and and then the bottom of the deep one line up with the bottom of the 2nd shallow one.

The lining up of the drawers is a guideline, not set in stone. It's your kitchen so you need to balance what works well for you with what looks good to your eye.
I think it would probably look good to my eye to change the lines when I turn the corner, I would probably still want alignment of the top drawers. Take a look at pictures of finished kitchens paying close attention to the layout of the drawers. Focus on your style of cabinet because it is different with inset v. full overlay v partial overlay.
It is great that you are building your own cabinets and can do whatever you want. You can probably also experiment(if you are not doing inset) with visually aligning the overlays but changing the interior drawer box size. Sort of like when one wide drawer really opens to 2 small drawers. I think beekeeperswife has a drawer in her kitchen which is really one very tall drawer but visually it looks like a 2 drawer stack because she didn't want to upset the "line".

It's interesting to see how really inefficient standard kitchen cabinets are. I measured one of my top drawers, first for the usable space, and then by how much total volume it took up. The usable space is 1069 cubic inches, but the total space is 3155, or about 3 times as much! That's an amazing amount of wasted space. I especially like the 2" of waste space above the drawer that nonetheless seems to have magnets to pull the BBQ tongs upward so they can jam. We won't even go into how much unused space there is in lower cabinets.

I can see I'm going to have to put some careful thought into the design of my cabinets and drawers to get the maximum usable space for storage. It does seem like 3-1/2" is about as shallow as I would want to go.

It looks like I would have 32(!) drawers at 4 per cabinet. This would give drawers of 3-1/2", 5", 7-1/2", and 9-3/4". Those are the actually usable, inside heights. Do those sound like good sizes? There would be 8 of each size, varying in width.

Added to that, there would be 2 undersink cabinets, a tall pull-out for baking sheets, plus the open space for sitting at the prep sink. I think I'm going to need bin pulls with labels to make sense out of that many drawers!

You need to get out your tape measure and your stuff. I own lots of things that would not fit in a 9 3/4" drawer. You also may want to consider where you want those things to reside in your kitchen.
For example, I bake a lot. The OXO containers I use to store my various flours and sugars are 9 3/4 " tall, but I really didn't want them in a bottom drawer. The bottom(motor) part of my Cuisinart and my blender are both taller than 9 3/4 inches. I wanted all this stuff in my island, so my island has 2 three drawer banks.
The more measuring and planning you do now the better of you will be. So measure all your stuff and write down which drawer you will put it in, to figure out if your plan will work for you.

Those sound like good drawer sizes to me, but as localeater said, you have to measure everything. The Cuisinart was my tallest item. I wanted to store it with the workbowl on the base, but I couldn't justify sacrificing one drawer for one item in my small kitchen, so it went on the counter. The other thing I had a problem with was an All-Clad frying pan because the handle angles up quite a bit. So measure handles when you measure your pots and pans.

You didn't mention your fridge cab. I store light-weight small appliances and baking pans(veggie steamer, ice cream maker, Bundt pan, angel food cake pan, large SS bowls, 6 packs of paper towels) over the refrigerator. Most people put dividers in their fridge cabinet for cutting boards and trays, but it really is the roomiest cabinet in a kitchen, so I used it for bulky items.

I have only one 3 drawer base, but I love the deep middle drawer as a bread and snack drawer. The top drawer in that stack is a spice drawer, which I also love.

The drawer sizes of 3.5, 5, 7.5 and 9.75 sound perfect to me and are roughly what I asked my KD for. I had measured all my cooking equipment carefully, and decided that a wide four drawer stack would work better (i.e. not require stacking the pots and pans) than a three drawer stack. But I recently got a gorgeous all clad pan, and I realize it won't fit in those drawers, so I'll have to find someplace else for it. I can see how there are pluses and minuses to making shallower drawers.

You've got 30" of space to work with, not counting toe kick space. If you do frameless cabinets, that will increase the usability of the drawers by getting rid of the face frames.

The usual division of drawers is in 6" increments as that gives enough depth to the upper drawer for a double stacked shallow organizer. When doing a 3 drawer stack, that's 1 6" and 2 12" drawers. With a 4 drawer stack, that's 3 6" and one 12" drawer. With a 5 drawer stack, that's 5 6" drawers.

Approaching kitchen storage from the viewpoint of toolbox storage can create a more useful division in cabinet spacing for your kitchen tools, but don't forget the aesthetics that result from divisions that create visual noise.

The tallest things I store in my kitchen that aren't pantry-type items and that can't be broken down are two stockpots, one 14" tall and the other 16" tall; I turn their lids upside down so the handles don't take up too much additional height. I suppose that those might fit into cabinets over the refrigerator, but they're both quite heavy (especially the enameled one!) and I would HATE climbing up on a stepladder and trying to balance while pulling them down or putting them away.

I'm not sure what the third-tallest item in the kitchen is. Now I'm curious!

A lot of the things you mention wouldn't be stored in drawers anyway. The KA mixer is too heavy for my wife, and stays out. The processors and other small appliances live in the pantry. I wouldn't enjoy lifting them out of the bottom drawers. We have two over-sized stock pots, and they likewise are stored elsewhere, appropriate to their once-or-twice-a-year status. Flour and sugar are also in counter-top containers, and will stay out.

We've cut way back on the amount of small appliances that we keep, getting rid of the ones that weren't being used. Even the KA and Cuisinart are only used a few times a year, although I can't imagine ever parting with those. My focus will be on everyday items- pots, pans, bowls, utensils, and dishes. In keeping with my toolbox analogy- you make room for the stuff you use regularly, and don't mind a short walk for the rarely used tools. Our stock pots live in the utility room, and it's no big deal to retrieve them.

I'm not planning for a cab over the fridge. Any cab that high is completely off-limits for my wife anyway. I might build a shelf with a gallery rail, and put some kitchen antiques up there. With 9'4" ceilings, there is a lot of room up there, though.

This is a kitchen for two cooks, but two older ones who rarely entertain. We also do a lot of outdoor cooking, with virtually all large cuts of meat done on the smoker, regardless of weather. Here is a preliminary sketch of our space-