I always leave out:
crayons
markers
color pencils
pencils
paper (white and construction)
recyclable materials
glue sticks
pom poms and other stuff to glue
I sometimes leave out:
beading stuff
regular glue
stamps and stamp pads
tape
stapler
scissors
My playroom is all carpeted, so we only paint in the kitchen
. I would love to have the paint available all the time, but we just can't. I'm considering buying some large area rugs for the playroom and then I would probably allow watercolor paints to be a choice.
My ages are all around 3 years old.
When I worked in a center we had everything out all the time. But, we also had easily wipe-able floors (and walls). If I had easily wipeable floors I would leave everything out all the time. And, yes, they do make a big mess.