Usually, I try to play at heads up or with just one or two other players, and sit on third base. I can keep up with the count pretty well, mostly counting each set of two starting cards after all cards are out.
When more than two other players are at the table, I sometimes get lost, especially when the first base guy takes a couple of cards before I'm through counting the starting cards.
I find it easier to track every card as it comes out, rather than counting the two cards at a time. But I've always tried to not "look like a counter", staring at every card as it comes out.
How do most of you track the cards/count?