[sweetjazz]

You need to get reads. Some players raise the turn with nothing with a very high frequency. You often have to call them down every time with A high, because they bluff that often. However, such players are not too common. I play late night, and I can often find one such player on at least one table I play at, but it's only those rare times when I find several such players at one table, or even find several tables with at least one such player who lasts for very long.

There are other players who play very passive and whose turn raises almost always beat TPGK. They are more common, but you (obviously) don't see turn raises from them as often. These are the opponents against whom you can toss hands like AK unimproved if you don't have outs besides the overcards.

Fortunately, while there are some players who bluff with closer to the correct frequency, they aren't all too common from what I have seen. (FWIW, I have only played ~6K hands at 2/4 and none at 3/6, and almost all late night.) These players raise the turn with strong hands and also with the occassional semi-bluff. You have to observe them more carefully, but if they play well then they will succeed in getting you to incorrectly fold AK some of the time. The main objective should be to sit at tables where there aren't too many players like this.

The only thing I can stress is DO NOT get in the habit of playing situations like you described the same no matter what. Being a good poker player requires you to recognize your opponent's playing style and adjust to it. You must take into consideration who is raising you. For the first 30 minutes at a table you might have to use default lines, but after that you should have some kind of read on everybody at the table that you can use to improve your decisions at the table.