So I'm trying to understand this concept since I think I am underbluffing certain spots and want to better understand what being balanced looks like.

Say in a situation I have two bet sizes, one of 50% pot and one potsized. Villain would have 25% and 33% odds to call, in order for his bluff catchers to have 0ev we would have to bluff 75% and 66%. So, the smaller we bet, the more we should bluff in order to be balanced. I do understand that applying this concept one on one on the stakes I play would be a misconception, just trying to figure out what balance looks like, so I can opt for a ~balanced line vs regs.

An additional question, how would we decides what hands go in to what range? Gut says the best bluff combo's should go in psb range.