The single most significant decision you'll make which will affect how much money you can win (or how much you are likely to lose!) is table selection. It's incredibly important! You simply must find a table where the majority of the people make more mistakes than you do. If you find that table you will win in the long run and if you don't you will lose. You can be a world class player but if you sit at a table where everyone else is a better world class player you will lose. There is no shame in sitting at a table under your skill level, quite the contrary that's where you need to be sitting!
Fortunately for you, in Low Limit Omaha players make lots of mistakes!
At first you are looking for a general sense of how things are going at the table. As you sit and play you should be constantly refining this estimate.
What to look for:
Opponents who play junk hands (especially random middle connectors like 6789, etc.)
Opponents who overvalue A2 with junk 3rd and 4th cards.
Opponents who draw to non-nut hands.
Opponents who never fold or who always raise.
Opponents who play well!
Usually you are making money from everyone who is playing worse than you and giving it to everyone who is playing better. That means that you should be sure that you are better than at least half the players at the table (and preferably better than ALL of them)
Remember: you don't need to play every hand!
If you are feeling frustrated from an especially bad beat, or the table is wild you can simply sit out. This is often a better approach than "tightening up" as the second or third bad beat in a row with "good cards" can easily drive any player into a bad poker-playing frame of mind.
Order some fries and a coke and sit back and watch. When things calm down take your blind and start again.
Do not play poker when you are not able to make good decisions!
That means don't play when anger and frustration are ruling your thoughts and especially don't play when you are bored or tired. Some players bring CD players and listen to music during the game. Do whatever it takes to keep yourself awake and alert and ruled by logic and not emotion.