Counting the pot is one of the most difficult things to do in a live game...Especially if you are accustomed to online where the pot amount is displayed for you. I've found that the best way to get better at this is forget the amount that is on the screen online. Try and follow the action and count in terms of bets (small bets/big bets) put into the pot. After some time, it really does become second nature so that if you are paying attention in a live game, you should know at all times what kind of odds the pot is laying you.