Basically the higher and more coordinated a flop is the bigger you should be betting. If a flop offers a flush or straight draw you should bet over 66% pot. If a flop is an uncoordinated rainbow with mostly low cards (ie: 27Q rainbow) you can opt for a 33% pot bet. If the flop is something totally ridiculous like 227 rainbow or 333 you can bet 25% because it is highly inelastic, and an opponents hand is either made or isn't and there are no draws for him to chase. So you can afford to bet less to induce a fold. The exceptions are calling stations who would call those small bet sizes regardless.
An elastic flop is one where the potentially best hand can still be made (this means draw heavy boards). Elastic flops require bigger bet sizes, you want to deny equity to your opponents draws while getting value if you do get called. An inelastic flop on the other hand is one where a hand has already been made or not made, so it's a flop with few or no draws, here you can afford to risk a smaller cbet size as that can generate a fold from opponents who haven't hit the board and won't be chasing any draws.
The bigger you bet the less often you must bet, which means you should lean towards betting coordinated flops with stronger holdings. Meanwhile you can bet low uncoordinated flops with a high frequency using a smaller bet size (if you had the preflop betting lead).
Edit: Just noticed you're talking about the turn (doh). Turns like bigger bet sizes
https://upswingpoker.com/small-vs-big-bets/
you should also consider your flop/turn sizing so that you can shove a big enough amount on the river.
And yes, to echo the good advice that others have already said. Some players are so bad they may fold to a minbet. Others are stations who may call anything. And for others yet you have to feel out what they're comfortable calling if you're value betting, and what they would fold to if you are bluffing.