One of the biggest mistakes many players make is overestimating the value of their small pairs. Small pairs (22 thru 88) really don’t have a lot of value in Omaha 8/b. This is for two main reasons. First, when you flop a set the likelihood of there being an overset is greatly increased by the mere fact that your opponents have four cards in their hand instead of two. Set under set is always a situation to be avoided. Second, and more importantly, is the fact that when you flop a set you are putting one piece to a low on the board. By this I mean that, by definition, if you flop a set of deuces thru eights there is necessarily at least one low card on the board. Why is this so bad? Because it greatly increases the likely the board will qualify for low and that you will be getting half of the pot only. Necessarily, if you get half of the pot instead of the whole pot you are reducing the odds the pot is laying you by half. Compare this situation to flopping a set of nines thru Kings. Then just the opposite happens: you are removing a spot for a low card to hit, thus increasing the likelihood that no low will qualify. This is why high pairs are so much more powerful than baby pairs.
Because of this difference between high and low pairs, low pairs actually weaken your hand rather than strengthen it. Even if your cards are strongly related to the pair, you cannot play. So hands like 8 8 7 6 are completely unplayable. This is despite having lots of straight possibilities, a possible set and two possible flushes. When you make a straight there is almost always a low qualified (e.g. the board is 456). When you make a flush it is never the nut flush. And when you flop a set there is a likely low available and it is rarely the top set. This is a hand you could fold in the big blind to a raise. You would certainly fold it in the small blind.
To play a small pair, the other two cards must have very strong low features and you must realize that the addition of the pair only marginally improves the quality of your hand. As an example, A 3 3 6 is playable because of the strong low features (A36) with the pair. Also, you have an ace high suit. But it is important to understand that this hand is not much better than having just A 3 6 with no fourth card! In contrast A 4 4 9 is only marginally playable because the low feature A4, is very weak. The 9 is totally unrelated. The only thing really going for this hand is the Ace-high suit. Because of this, this is a hand you can call a raise with in the big blind. You can call a raise out of the small blind if the raise has come from a steal position. You can limp in late or in the small blind. And you can raise from late when no one has entered in front of you. But you should not otherwise enter the pot.
Hands like 2 2 3 4 and 6 6 2 3 are even worse than the above example. Even though you have lots of low cards working, you will only flop the nut low draw when an Ace hits and it is never a good idea to be relying on exactly one card to hit the board. When you make flushes with these hands they are never the nuts, unlike with the A 4 4 9 example. Your sets will always be weak and when you hit them there is a likelihood of a low qualifying. These are hands with huge negative implied odds. You will often end up chasing half the pot with the second best hand and just paying off to the nuts, as when the board is 4 5 K 7 Q. Even with the 2 2 3 4 you still only have the third best low (A2 and A3 beat you) and you have very far from the nut flush. You will often be scooped in this pot yet you really have to pay it off even so because you hand is a two-way hand-it could be best for high or low. Therefore, these hands should only be played from steal position or in the big blind. You should never call a raise with these hands unless you are in the big blind. This is particularly important since hands that raise in Omaha 8/b almost always contain an Ace and this, by definition, takes away one of the four aces you desperately need to flop!
Hands with small pairs and very weak low features are always unplayable unless you are in the blind or in steal position. So 8 8 A 5 is absolutely terrible. You have no suit, a small pair and a terrible low possibility. 6 6 5 A is similarly bad even with the ace-high suit. Don’t be fooled into playing these hands just because you have two wheel cards or an Ace high flush possibility. You are essentially playing with only two useful cards in your hand, which is almost never a good idea unless you have exactly A2.