Definition of set-up
A set-up is a frustrating situation that cannot be avoided. A set-up is a "mise-en-scene". In short, you play a hand and the hand plays itself, both for you and for naughty. There are several type set-up situations. One of them could be a set over set. A player opens 99. Another player 3bet QQ. The player with 99 calls. The flop falls Q-9-2. Here no player can folder. Both are convinced they have the best hand. It is a set-up in the sense that the situation is inevitable. You have to take these situations with a good philosophy.
How do you avoid set-up?
The answer to this question is that it is almost impossible to avoid them. The good news is that the set-up's will go both ways. Sometimes it will be you who will lose your carpet with the worst hand, but sometimes it will be you who will be on the right side and have the best hand. Don't avoid the set-up. Ten's are rare, and each time, none of the players involved in the hand can folder. If you have 55 out of 5-5-7-7-x, you cannot fold your hand because your opponent might have 77.