[pfapfap]

eg, ie, fu.

(it's a movie reference)

Anyway, I find what works for me is being a bit of a nit, but explaining why rules are the way they are. Save the explanations for after the hand, but explain why it's a rule and gear the explanation towards the person (e.g. if you had a flush and someone else didn't realize there was one out there, you wouldn't want someone else alterting them... or if you splash the pot we won't be able to tell how many chips you put in, which could end up being unfair to either you or the person who wins the pot). Don't talk down to them, maybe even seem sheepish about having to bring it up. Be understanding, just make it clear that you're trying to keep the game clean and fair and efficient so that everybody can have a good time. Perhaps suggest that you've seen some nastiness resulting from some of the rule violations and you don't want to see that happen.

Tailor it to suit your personality, of course, but I find the above has generally worked for me. By and large people will respect you as it's your game. Most of them even want someone to step up and take charge. Don't be afraid to do it.