It depends how multiway the pot is. If theres 3-4 limpers you can raise and probably make it HU on the flop then raising is good.

If you are at a table where there are huge numbers of limpers who will call raises with marginal hands then you should be seeing alot more flops but raising with alot fewer hands preflop since you can wait until you make your hand and then make big value bets that will be called by weak hands.
At a table like this I would probably limp TT (maybe even JJ), but also limp alot of suited connectors / suited aces etc.