I did all the above tips when I taught myself how to paper piece plus some. I purposely used see-through paper so I could see that the fabric was going to cover. I also cut up some foundations to use as templates to make sure I got the angles correct & cut large chunks to make sure I had enough fabric. Cutting up the foundations to make templates helped me the most but I hate template cutting and only resort to it for those oddball angles.
I crease all my seam lines before I start so I can make sure the fabric will cover and I trim each seam before attaching the next piece. I also use glue instead of pins for the sub units. I will pin intersections of sub-units but I try to fold back or pull the paper out of the seam lines before I do that.
I also had to use the see through paper or trace the lines & numbers on both sides of the paper so I wouldn't get confused.