The classic hold'em player's mistake in Omaha is to over-value hands; dynamite hands in hold'em can be little more than damp squibs in Omaha.

The worst of these is a weaker full house (sometimes called the underhouse), as these can be extremely costly. If you flop two pairs, especially if they're mid-pairs, your hand is next to useless if you have more than one player left in the hand. Even if you make your full house, it's likely to be beaten. The same goes for mid and low pairs. If you hold 8♥-8♠-7♥-6♦ and the flop comes K♣, K♠, 8♦, you currently have a pretty strong full house. Anyone holding a King will probably call a pot raise and then the turn comes a Queen, and suddenly you could easily be losing (in fact, even someone left in with Q-Q will now beat you). Remember that Kings full of anything will beat you. Play mid pairs with extreme caution.

As an aside, I prefer playing with small pairs (5-5 suited and below). This is because if they quad up, you can make some massive pots from players with A-A suited and K-K suited who hold what they think are unbeatable full houses. At the same time, their obvious weakness means there's never any temptation to overplay them. Low pairs can be profitable starting hands if you can limp into pots cheaply.

It goes without saying that non-nut flushes – even King high – aren't much use in Omaha, despite being mighty in hold'em. Further, bottom straights are worth very little – if you own the ignorant end of a straight you should call only the smallest of bets on the river, if at all.

Except for quads, it's always a good rule of thumb to assume you're facing the nuts in Omaha, especially in multiway pots, so bluff with extreme caution.