kellied, I have the same situation you have. When we remodeled 3 years ago I had a murphy bed made for the room. I didn't see the sense in making a sanctuary for someone who may warm the sheets 10 nights/year. Now it's my sewing room. About 90 percent of the closet is my storage space. When the bed is folded up I display one of my quilts on the outer surface -- it is finished hardwood. It also serves as my design wall when I am in quilting mode. When the bed is pulled down I move the quilt to hang on the wall behind the bed. That gives the space a homier look.

I've organized my threads in rainbow order: ROYGBIV (red-orange-yellow-green-blue-indigo-violet) on a large wooden spool rack. This is actually pretty to see coming into the room. Some of my sewing tools are hanging on a pegboard I framed and painted to match the room; as long as I don't over-fill it I don't think it is off-putting for a visitor. (My most frequent visitor is my sister, a big-league quilter. She loves staying in this room, and in fact calls it her room.) White plantation shutters on the windows are both pretty and practical -- keeping sunlight off my quilts and fabrics. When tilted open they reveal a nice view of my two citrus trees. I still need to get a small rug, only to be used when a guest is in residence. Otherwise it would be a lint and thread catcher waiting to trip me. I wish there were a sewing room forum here. In fact, does anyone know how to start a new forum? Bonnie

I wish the sewing forum got more traffic ,,, you might want to search the quilting forum too (it seems like that one is more active).

I use my 1st floor guest bedroom for sewing. The machine, attachments, and doodads are "hidden" in a piece of furniture (looks like a hope chest or storage box/bench). And then about a third of the closet is used to store material and projects. Also in the closet is a folding wooden card table that I set up when it comes time to sew. The room always looks like a bedroom (you can't even tell by looking at it that I sew in there). This sort of works for me as I currently don't sew that often (just learning). One thing that I didn't think about and is rather a pain for me is that my laundry room (w/ ironing board) is up on the 3rd floor of my house.

As far as the guest room aspect besides bed/futon and bedding, consider a side table w/ lamp, kleenex, water glass, & alarm clock, surface space for their luggage, a chair, access to outlets (to charge cell phone, etc), full length mirror, hanging space for clothes, maybe a night light.

Dedicated sewing rooms (most that I've seen irl) can be quite messy (lint, loose threads, dust, etc...) and junkie looking with projects and material piled up everywhere. So that's something you'll want to manage if planning to share that space with guests.

I am ripping out the carpet and putting in laminate flooring so I can stay on top of dropped pins, loose thread, etc. I am much more likely to run a Swiffer than I am a vaccuum.
Good thought on the full length mirror. I can hang it behind the door so when it is open I won't see it but guests can use it when they close the door. My cedar chest lives in there for luggage or perching plus a comfortable upholstered rocker/recliner that I use when I hand sew or crochet. It is smaller so the room doesn't feel crowded.

These are good ideas and I can use more!
Off to check out the sewing forum. I'm a garment sewer more than a quilter. Maybe I can help liven it up over there!!

Sorry not able to post any good links, but I have seen (and ripped) a lot of nice magazine spreads on just such multipurpose rooms. Good features are multipurpose furnishings, furniture that can be moved around or re-oriented easily (lighter weight chairs, table that can move to be bedside or writing table) storage cubes, rolling files, using hidden storage (as you are using closet).

The other thing that to me makes the rooms look fun and inviting is using nice furnishings and avoiding the mish-mash, castoff junk room look. That can mean investing $$, but maybe more to the point it means being intentional, and thinking about what would best fit the use, the space, and the decor scheme--keep your eye out for just the table or chair that would be right, editing until you have the look you want and not just tossing in all your spare stuff; painting items to match, using fabrics to coordinate, picking art or photo frames specifically for the space. These are all generic decor concepts as well but can take more effort to stay focused in the multi-purpose room.

Another sort of operational concept is, make it easy to do a rapid clean up for guests. In my study-guest room that means several things--1) keep after it to not have too much stuff or random stuff drift into the room, also not let my project ADD get out of control and have too many things pulled out at once--a constant battle 2) I keep some dedicated EMPTY closet and shelf space with empty baskets or empty plastic bins, already labelled as "empty" (yep) or "stuff to sort and put away" for the specific purpose of being able to a whirlwind pickup when you just don't have time and energy to do a precise pickup and putaway.

Pattern Review does have a "Sewing Spaces" forum with some ideas for sewing room organization. I think the root of the problem is that we're all at a loss on how to keep them organized though!

Honestly- is there some other space you can put the guests in? There are rooms that can do double duty, and my sewing room is not one of them- I've decided that overnight guests would be more comfortable in the bar. Or the Red Roof Inn around the corner.

Here is a link that might be useful: Sewing Spaces forum on Pattern Review

The only people that will likely ever spend the night are ones that would be just as happy to crash on the couch or would love to rummage in my fabric stash. Anyone else, local hotel! I highly doubt we'll get anyone staying more than once every couple of years but I want to be prepared if spur of the moment I'd want someone to stay.

We did decide not to put up a permanent shower curtain rod in our hall bath but put up a tension rod on those rare occasions someone will be taking a shower.
Thanks for the link to Pattern Review. I'll go check them out!