How much should we bet to properly represent the flop? It depends on how serious we are on representing the flop.
First of all, representing the flop means we project the impression to everyone at the poker table that the flop is helping us a lot. We convince them of this by placing a bet. Thus, ably representing the flop means we make the bet convincing enough for everyone at the table. The right representing bet should be realistic enough - not too small as to be negligible and not too high as to render us pot-committed and keep increasing our other bets exorbitantly.
When we convince them that the flop is helping us, they get the impression that we're about to hit a monster hand. That's the effect we want here. To have this effect we must first make sure that we don't place a minimum wager post flop. This is a weak way of representing the flop. We want our bet to scare away weak hands. But we should also see to it that it's not too high as to obligate us to be too protective of our investment in the pot.
The key here is to face the fact that our bet for representing the flop may be lost money. It's a big risk to take. The risk may work or it may not work. We should try not to worry about this amount anymore once we have used it for representing the flop. Doing so would only make us give away poker tells opponents would capitalize on. But this is not to say we intend to lose in the game. We just prepare ourselves so we don't get too frustrated, just in case.
For instance, we have a suited 9-8 and the flop says K82. We're first to move. Checking will make the player after us bet. We don't want that, so we opt for representing the flop with a good bet - not too high to lose too many chips once something like an A4 turns up, or too low that we don't scare weakling hands away. Without a player with a K and a kicker, maybe everyone would fold.
So, remember that representing the flop means we do so with a good hand that may be improved on the flop. We do this to scare weak hands out of the hand and also project that a monster hand may be forming in our hands strong enough to win the pot.