Closets- freestanding pieces that look like built-in closets. Tons of options to personalize them.
SketchUp was a natural choice for me because A) there is a robust version available for free, B) I have seen many example drawings that represented exactly the type of projects that I wanted to design with the tool so I knew that it was capable of performing my intended tasks, and C) because it is so widely adopted, there is an abundance of free and inexpensive self-guided training materials available.
DIY pipe shelf construction- this might be the perfect solution for a cheap, large storage/ desk space in my office. I would put a thin pipe in front of shelves to hold things in place. This would make a fabulous pantry - wall-to-wall, floor-to-ceiling!