Never underestimate the importance of dry firing. It's like a boxer, spending hours upon hours on the heavy bag, speed bag, focus mits, etc...
I've read and believe that dry firing helps condition you to not flinch in anticipation of recoil. I like to balance a penny flat on the top of the slide, and practice dry firing that way.
X2 on mixing snap caps in your magazines. I like to mix snap caps and spent shells in 5 different magazines, then mix up the magazines so I don't know what's coming.
Of course, always practice the fundamental safety rules when dry firing. 'I thought it was empty/ thought it was just a training round.'. Is heard way too often in my opinion.
I might get some heat for this, but if you can't get to an instructor, I recommend getting the Magpul pistol training DVD. I've been shooting for over 2 decades, and still learned a lot from that DVD.
Arbitrary enforcement of the law is the mark of tyranny. Citizens will always fight against it.