I've seen lots of things that I did, and some I still do, dang it.
When I started shooting (pistols), I read everything I could find. Libraries, used bookstores, and even gun rags (they used to actually have lots of usefull info., not just tac/ninja accessory articles). I think the 2 best pieces of advice were: 1. Breath control, and 2. Front sight.
I remember it took me forever to get the take a breath and partially exhale bit.
Now it's just natural.