re: Poker & Bet sizing in later stages
This was just bad luck. Bet sizing is OK. However, AQs is most probably a flip if you don't hit an ace or queen. You will be behind all pairs. The good news is that you did hit the flop, which is quite good, and I think going all in there is OK, since you expect to get paid by KQ, JQ or mid to lower pairs. Bad news is that you didn't expect the other guy to have a set. Now, I don't think a 3x bet preflop would have changed things. If I am in the button I will call with ANY pair to an open raise. I will certainly 3bet with top pairs, but the only way I am folding a holding like pocket 6 is if someone open pushes with a stack similar to mine. So then, if you opened push here with your AQs you would have probably had no callers, and you would have just collected the blinds, not a good idea I think. Too risky. It was better to open standard (you did) and hopefully hit the flop (you did) and get going from there. What if instead your AQs you would have been dealt pocket aces? You would have probably played the same, and would have been busted all the same against the set of sixes.
So, the bottom line IMHO is don't worry about your bet sizing. It was pretty standard for that stage. Everything was standard, you raised a good holding, you hit TPTK, you were only called by the button who probably has a wide calling range being in position, everything is set for you to take down the pot, except that your opponent was lucky enough to hit a set. GG.