Consider your image. If you think your opponents will start thinking, geez this guy hasn't played a hand in an hour. If he bets, I'm autofolding. A good time to bet with any hand that has potential to hit the flop. Say suited two gappers, ax suited, small pocket pairs things like that. I might even do it with Kx or Qx but that's about the worst I'm going. Probably what will happen is you'll raise preflop and everyone will fold, but on the off chance you get to a flop you don't want to be holding two cards that won't even make a straight.
Don't overdo this, but occasionally will help you still get action when you finally do get a high pocket. Of course if you're really frustrated quitting the game is probably the best option.
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