the reason you need to raise more pre-flop is probably the reason you dont. i suspect you arent raising often because you wait for a good hand, and when you get it, you think to yourself, "man, now that i have it, if i raise, it will be too obvious, so, i should just limp in, and throw them off." could that be right?

if so, that is the reason you need to raise a lot more hands, and some marginal hands before the flop, especially if the others have all folded around to you so far (first one in). you raise some weaker hands before the flop to "disguise" the times you DO have a monster. plus, if they dont know what you are raising, but know there is a high possibility that is a very strong starting hand, you can win a lot of pot right there on the flop with a 3/4 to pot-sized bet, even when you miss. your opponents will have a much harder time guessing whether or not you connected on the flop, and will see that they have to pay a hefty price just to see if their "hunch" was correct. most wont do that.

when they start messing with you and raising your bets (to put you to the test), then you either back off a bit, or raise a little more pre-flop, or re-raise their raises to put them back on the defensive. you start mixing up what you do in response to them...but those are other topics for a later date.

check out the thread of "aokrongly's starting 19." i think its stickied in the beginners forum, if not, it used to be on FTR's front page. while that is too tight for a 5-6 handed game, it gives you a good idea of the most profitable hands, and therefore, which ones you should be raising frequently. or at least a place to start, when changing some of your philosophies about the game.

good luck.