The great majority of my students who are experiencing disabilities try hard and participate and do well.
The main difficulty I have had is with those few students on IEP's who exploit that designation to do absolutely nothing. Nothing. I mean nothing. not even in art. They don't have to. And then they get angry because I won't let them play cards or sleep in class, which is all they want to do. And it makes the other students intensely frustrated since they know those kids will never flunk or be held back, they still get to go on field trips or whatever. They are royalty.
I've also had difficulty coming up with enough different work for the students who have to go to the student alternative center or saturday school due to continual behavior issues yet they can't read. I have designed a few puzzles, but I'm finding it a real challenge. I don't want to give them pages out of pre-reader workbooks because they look so babyish, and think they should have to do more than art history coloring pages, but how to balance content and no text? Over and over and over?