He'll get there. Don't forget you probably use them a lot more. I was clueless too when I started... took me ages to realise that the BumGenius Freetimes have the lines in the boosters so you can fold them to make them thicker at the front/middle for a boy/girl!
I taught my H how to do the pocket nappies and he is good now, and we mostly use all-in-ones as that's easier. He does the night nappies too.
It is confusing if there's loads of different types, he only used the Freetimes to start with and then slowly I showed him how to do the others x