Best resource: post hands and ask about bet-sizing.

It's all about charging Villains more when you have a reason to think they're drawing. When the board is such that most of Villain's range is made up of hands that are drawing to a straight or flush, then you want to bet an amount that makes calling and chasing that draw a bad gamble.

In general, a player is going to raise, fold, or call based on 1) their cards and 2) the board texture (QQ tends to shut down when an A or K comes out). The amount that they are willing to call is a distant 3 in their mind, maybe causing them slight hesitation before doing what they had already decided to do before they saw your bet amount.


So, when the board is wet (has lots of draws), you bet big.
Villains will call more than they should, so you make them pay for it big time.

When the board is dry (rainbow board, no straight draws), you bet small.
Villains will only continue with strong hands, so you don't want to spew into them.


Another upshot of this is that Villains will see you varying your bet size and assume you're doing it based on your hand strength. So you get even more benefit by exploiting their mistaken read.