Blocking bets

[JAP]

Are they really useful, do they keep players from bluffing or do blocking bets induce raises? How much do you usually bet 1/4 of the pot? When is it useful?
I usually dont block bet because i reason if i check i might pick up at small/medium bet that i never would've gotten a call with so instead of betting and only getting a call or raise with a better hand i check and try to pick up something.
And i dont really see a bet blocking anything if a player wants to raise they raise. and sometimes on a pure bluff because they think you are blocking.

Ok opinions please.