It is a very rare thing to overbet the pot. I Can think of several ways it can be effective and where you shoudl and shouldnt use it.
Firstly, the most effective way to use it is when you have the nut hand and you are playing against a loose player who doenst give you much respect, especially if you have been playing loose yourself this could end up being a big pay off. Something like betting ALL IN when you have hit the nuts on the river by hitting a gutshot straight or a flush card to give you the nuts.
Secondly, you could use this as a bluff. If you are playing against some rather tight players and need to act as though you have hit the nuts when the flush card hits the river just to give the perception of you having the nuts. This is the best way to get the bluff to take hold, although and overbet vs a value bet on the river when you have the nuts is a risky endevour, you have to make sure you are bluffing a person that can be bluffed first of all, and you have to make sure you have represented the hand appropriately, sometimes this can come to be by mistake and just so happens you called the flop and checked the turn and notice that a flush draw is available with a river card completing the flush possibility, or you could notice it on the flop and play to the fact that you CAN represent the flush if it happens to hit, in this case an overbet could be very effective to take down a big pot, if you dont put your opponent on the flush as well or any other nut hand you are trying to reprsent (flush being the easiest to represent).
Lastly, An overbet could be used early in a hand to represent a bigger hand when a weaker player bets out of position, If you raise a big raise on the flop early in the hand it can easily take the player off of their hand giving them no pot odds
to call early in the hand without draws and just a top pair or so with not so great of a kicker. This is usually done without using an ALL IN because you dont want to put all your chips at risk unnecessarily. If you do this bluff or even bet this scenario i would do it by betting something like 4x the pot after the player has made a 1/3-pot size bet on the flop. If you decide to use the overbet use it sparingly and only in certain situations as i have described above. I would stress using it mostly just in isolated situations because if you do it with multiple people in the hand it just gives them a chance to be holding the actual hand you are trying to reprsent. Good luck and try your best to use it effectively in limitted situations.