If you need to design a shelf, or plan a repair in an apartment, use SketchUp. I have never seen such speed, simplicity and accuracy of modeling anywhere, and I have something to compare with. There is a small entry threshold in the form of an unusual approach to modeling and several basic tools that you need to learn how to use, but then the program reveals itself in full. This knowledge would save me a lot of time, I wish I had it earlier.