Knowing your math. Basic draws.

[fees]

Hand 1: This looks like an easy call, we are getting 3:1 and thats about exactly our odds to make our hand. We also have implied odds from river bets.
Hand 2: Sub Q: fold. I think I just fire this, My guess is he probably called preflop with the intention of floating a veriaty of flops. I think his range is probably weighted towards small-medium pairs, some SC's and maybe a KQ or AJ type hand. Since we can fold out most everything except KQ and AJ we can profitably bet 30 as the only hand i expect to call is AJ, which we have outs agaisnt. I neglected him having a set here, which he very well could, I wouldn't triple unless I hit a king, so I think its a pretty easy b/f turn and c/decision river.
Hand 3: I think I call here planning on bluffing the flush rivers.