The way to end shoe moulding is to cut as if you are at an outside corner, and then cut a reverse of that so that it returns into the wall. It's like an outside corner except the piece that runs perpendicular to the wall is only as long as the corner itself, if that makes sense. As for the door casing, I would handle a door and a doorway (ie no door) differently I think. In the case of a door, I would stop shy of the casing, in the case of a doorway, I would run up to nearly the end. That is more of a personal quirk though.

Hi,
There are only a few times when it would be appropriate to run the shoe into the area of the casing. In a small number of trim jobs, the casing will be the exact same thickness of the baseboard, and this casing will have a portion of square (plain) profile at its edge before the molded portion begins. In that situation, it's acceptable to overlap the shoe onto the flat portion of the casing. This is encountered in old houses.
When there is a deep backband molding atop the casing and running to the flooring so as to make a natural stop to the baseboards (and the shoe) it would be prudent to stop the shoe into it, rater than making lots of little miters to run around it. Same goes for thick plinth blocks. If the amount that the plinth block sticks out beyond the shoe is less than 1/2", you need to "ease" back that portion of the shoe that projects clear of the plinth so as to give a neat appearance with no sharp transitions.
The basic way to and a butt cut on shoe, where the entire end is seen, is to leave a 1/8" flat of shoe and miter the rest at 40*, not bringing the shoe to a complete point.
The ends of the shoe, if you have the ogee shoe or if the work is very fancy, would be to form molded returns on all ends; instead of easing with a 40* cut, the profile is repeated to resemble a mitered return where the molding turns back into the wall. This is done by carving the shape into the end grain, not by glueing in a tiny sliver of molding.It must be "worked in the solid" as they used to say.
If you have a column base in the middle of the floor, let need dictate using shoe. Only if the joint or scribe of the flooring up to this object is wanting should you lay shoe mold there.
More than you wanted to know, I'm sure.
Casey

In my "new" house, we have plinth blocks at the doorways. I just walked all over looking for an odd transition, but the shoe Mould runs into the plinth and stops, and it looks very tidy, not like an odd transition. We have dark walnut floors and creamy baseboard and were given the choice of painted or stained shoe moulding. We chose painted and I think it is a great way to go because it makes it look like baseboard detailing vs. your floor curves up onto the wall! Not that you asked, but in case this is a decision you are about to hit as well....

Thank you, Brickton, Casey, and mythreesonsnc. We did choose painted shoe to match the base, but the way it was installed was a bit odd, I think. He didn't do it the same way in every instance, and I'm trying to figure out a good way to fix it.

I think the easiest way might be to cut five inches off the bottom of every case moulding while they are still attached (if possible), and attach a 5" tall, 2.5" wide plinth for the shoe to butt up to. But I haven't found a deep enough plinth yet - I need 1.25" or even better, 1.5" deep. Plus on some shoe he mitered, on other shoe he sawed it cleanly without a miter, and on still other shoe he mitered just a bit of it, not the entire edge.

I also think that the idea about returning the shoe back into the wall would be great - we will do one of these two ideas, but I don't know which yet.