Texas Holdem NL (no limit) play is about as different from PL (pot limit) and FL (fixed limit) as it gets. Never be arrogant enough to consider that you will be able to beat No Limit, if you are a successful player at low-limit FL tables. If FL is your game, you will pretty much have to learn poker all over again, when you move on NL play. There are certain strategies that work wonders in one type of Texas Holdem play, and spell disaster to the player using them, in the other.

To save you the trouble of going through 3-4 pages of text, I’ll give you an example which will hopefully shed some light on what I’m trying to say:
Consider the “strong pre-flop play” strategy. We all know how it is supposed to work in NL (if you don’t, pay attention below) and those who understand why it is a good move in NL also know that it’s utterly useless in FL.
By strong preflop action, good poker players try to create a much better position for themselves later on in the hand, in the post-flop betting stages when every small edge really kicks in hard.
They achieve this by raising a lot preflop and by generating some apparently senseless action there.

These preflop moves are basically a double-edged sword: on one hand, they cut back on the number of rookies that will later team up on our good player. Obviously, some of the players in the game will fold, compelled by the action generated. The fewer players remain to see the post-flop betting stages of a hand, the better the odds are for those who stay.

On the other hand, the same move capitalizes on one of the most widely-spread anti-skills rookie players possess: the willingness to commit pre flop money on a hand, with the goal of taking a peek at the flop, but folding as soon as the flop misses.
This will leave a lot of dead money in the pot, further increasing the odds for players sticking around till post-flop betting.

Why this same strategy won’t work in a FL game, I think is quite obvious to anyone. You can’t really generate intimidating action when there’s a fixed cap on how much you may bet.