I wish I had easy storage for projects in progress. I often have several projects going at the same time and don't want to always fold things up and put them in bins to keep my workspace neat. Some sort of large doors or hangers or shelves (or all three) where projects can go and be neat, but easily accessible is really important.
I notice that someone said a closet. I'm glad I have a closet to keep the miscellaneous stuff I don't want to see constantly, but I wish it had folding doors or something other than 2 sliding doors. If what I need to get to is in the middle its hard to get out and half the time I have something on one side and another thing I need to get to is on the other side. That means I'm constantly sliding doors one way or another to get to stuff. also, sometimes its too easy just to shove stuff in the closet, which means it gets junked up. Be careful to have an actual place for things.