wood that was about 3/4" thick cut into three sizes. How to make a shelf. Diy Mounted Shelving Unit - Step 22 we then hung the uprights after measuring and remeasuring and leveling and stud finding and then i sanded and stained 12 pieces of wood. we live in an apartment with a small balcony. so yeah. that took a day. wood was ready to go and we then decided where each shelf would go, and screwed the brackets to the shelves. and that’s about it!