The dental floss is basically tying floss around the bucking to create a better air seal. You only need this if you want more fps, which won't do much for you. You can find a guide on the TDC mod in my sig, it is a very good idea to do it. You can also follow the guide on the one piece wax barrel spacer LRB, minus the LRB for now. The wax spacer has proven to be one of the most effective in both performance and cost, and is easy to do. As for the hop arm shims, you basically use something as a spacer, be it strips of (my favorite method) scotch tape, aluminum foil, or brass shim stock. The idea is to center the hop arm over the bucking and give it no side to side play. Some people also shim the inside slot but if you do the TDC mod you won't need to.