Message Board : Floating on the Flop for a Turn steal

When reading the series on pre-flop standards for OTB, against an aggressive player making normal size raises with 100BB stacks, there were quite a few marginal hands like 98o or A2s or 64s were advocated to be played on the basis that we could use our position to punish our opponent. Since our opponent is aggressive, we can reasonably expect him to cBet a lot of flops even when he misses. A lot of these flops are missing us too. What should we be looking for calling his cBet, and going for a Turn steal?