All Purpose Grow Room

Anyone has some suggestions on usage of extra room? Currently I started with a 6 x 3.5 x6.5h room.
I currently have 2 plants growing. Anyone has suggestions on if i could build a drying rack/room that is light proof in an unused section. The reason for this is I have several auto’s that I feel we be finishing at different times and not sure how to handle that so wanted to think ahead.