This week I finished problem set 2. The parts in this set taught me how to use the line tool to do things in less steps. For example, if you need to extrude a square in the middle of a block, you could take multiple steps to extrude a larger section and cutting it down into the center. On the other hand, you could draw a line to where the square needs to start and use that as an anchor point. This lets you do many more actions in one extrusion.