I recently took apart a new two piece ball valve and removed a ton of tape from one of the male pieces.
I need to add some plumbers tape to it and I’m curious if the tape should go on the very end of the male piece or midway up? I ask this because previously the tape went to the end of the part and pieces of looses tape were hanging in the valve.
You want to wrap it towards the end without going over the edge. Going over the edge is not a big deal, but you can avoid it. The tape seals and also lubricates the threads making it easier to tighten.
This actually just came up… Not that you care, but to be code-compliant you have to have a double spiral over the entire active threaded section, with both ends visible. Overlap is unnecessary and could cause problems if it gets excessive. Remember to wrap with the threads (clockwise when looking at a right-hand thread) so that the tape tightens rather than loosens while threading on the fittings.