I remember when I first started playing for dollars rather than quarters; I slowed way, way down. I do remember a few mistakes that I noticed just as I hit the DRAW button, they can be an expensive lesson. I remember once holding a dealt flush, only to find that the machine didn't hold one of the cards (lots of machines have poorly-working touch screens and/or buttons); that was a $30 mistake that stuck in my craw for a while.
I agree wholeheartedly with Rick; if something with significant potential shows up (like a four-flush, trips, any decent dealt hand), I slow WAY down and especially double-check that all the held cards are indeed held.
The other thing that's helped me is that I've started playing DB more, and you really have to slow down in that game, there's too much that's easy to miss. I'm getting faster at it, but still slow; I'll usually first look at the lower half of the cards, i.e., the suits, to make sure I won't miss a 3-flush. Then I'll read the cards to myself in order; if there's an ace, I'll read it twice, low and high, to make sure I don't miss an inside or outside straight. It's getting faster, but I'll never be a speed demon. As Rec says, there's no prize for playing fast, unless you're always playing at 100%+, AND are in it to make as much money as possible. Even Bob Dancer says that an hour's profit can be easily wiped out by one error from playing too fast.
