I'm new at breeding but not at owning ball pythons, as I got my first one back in 98. It also took me a while to get it down but once you do it's as easy as anything. The biggest issues I've come across would be that larger males tend to "fight" if you will the popping process by holding those penes back. Some males are extremely good at this, so it can be more difficult with them. Another issue is small penes. Just like humans some males are blessed with a tree trunk while others get a branch so if it's penes are small it may be difficult to see them popping out. That being said I would just practice more, I know you said you watch videos, but if you haven't watched Ralph Davis do it I would recommend his video cause he makes it simple(that's who's video I watched over and over to get it down) I left a link of two of his video's the second one I like cause he pops a small and a large male. Hope this was helpful and good luck with your future projects!!!! http://www.youtube.com/watch?v=wMqN402TiVg
http://www.youtube.com/watch?v=BPmIpc_gP9I