Here is something I put together a while back based on my results and what I have read in the past.
This is not the last word on O8b starting hands. Much of the comments are debatable There were no equity calculation made or simulations ran on these hands.
In the loose passive games I like to play, any A2 is playable from any position. While you like to scoop, playing nut lows will show a profit in loose passive games. Just don't jam the pot with a low only.
Having a suited Ace in your A2 greatly inceases the value of your hand as does additional low cards or high cards. Hands like A23x or A24K are excellent starting hands. With hands like A23x with a suited ace, I like to raise in late position to build a big pot but limp from up front to let oppoennts in. Even with the beautiful A234 I want a lot of opponents. You have a great low hand with a good shot at a 5 or 6 high straight, or a flush with a suited ace to scoop. Let the lesser hands in and hope to scoop or 3/4 them.
The addition of a big card like A24K, A2KK (queens and jacks are good too) or A2 with two broadway cards gives you hand extra heads-up value and you can raise to limit the field. If other player call, that is fine too especially when suited or double suited.
A3 hands need help to play. A suited ace or another wheel card are required to make A3 a playable hand.
I hand like :ac :3d :5c :js is a good hand. Just remember when you play post flop avoid drawing to the second nut low if your hand has nothing else going for it. A34x even without a suited Ace is also playable if the x is a 5,6,J,Q or K it is a fairly strong hand.
A4 needs a LOT of help. A suited is critical, along with a 5 a big pair, or two other big cards to be playable.
:ac :4c :5s :kd
:ac :4c :kd :kh
Of course being double suited is even better. Even with the addtional help, A4 should only be played from late position or the blinds.
2345, 2346 and 2356 are the only 23 hands I will play (not counting big pairs which I will talk about below). They are weak, and for the most part you need an ace on the flop to continue, but they have shown a profit for me.
The big hands
For big cards you only want to play hands with for cards ten and higher. AKQJ,. AKJT, KKQJ and such. Having a pair or suits greatly increases the value of these hands. KQJT with no suited cards in O8b a lot like KJo in limit holdem. You will often hit a flop that looks good but end up getting out drawn by the river. The big cards are not raising hands. You want to get in cheaply and try to scoop a big pot.
The Trouble with Trips - the Big Pair Hands
The AA hands
Virtually all hands with a pair of aces are playable in O8b. There is a lot of argument of the junkiest of these hands, hands like AA79 and AA98 with without suited aces. Many people say to play them from any position, but I throw them away quite often as they are hard to play post flop, and you usually end up fighting for half the pot.
When AAxx is combined with a 2, 3, 4 and a suited ace, you have one of the few hands I will raising and reraise with in O8b. Me opponents can call or fold, I really don't care. When combined with two other cards ten and higher and suited ace you also have a pretty strong hand. Any AA hand with a suited ace is playable regardless of your other two cards.
The other big pairs KK and QQ.
I consider sets to be drawing hands in O8b. When you flop a set to KK or QQ, there will either be a low draw or a straight draw on the board - and possibly a flush draw too. You really want to hit a full house with these big pairs vs a lot of opponents. I wont play a KK hand without it being suited, with two wheel cards or double suited. QQ I consider marginal and can be tossed anywhere but the blinds - an exception could be QQ23dsr QQ24ds in late position for one bet. Just remember that you are not playing these hands for the flush potential, but the flush can give you redraws if you flop a set and back into a flush that may be good.
A2 is a dangerous combo in any Omaha hi/lo hand if you ask me. I always end up getting quartered cause some other guy pushed with A2 also. I tend to stay away from betting the low hands unless there`s potential for the wheel. Three cards in the A-5 range is worth seeing a flop though.
Play hands that can make both the nut low & a strong high. If you have a high only, you're setting yourself up to get freerolled, and if you have a low only, you're setting yourself up to get quartered.
And I disagree with Beavis that 23XX hands are weak. I agree that in limit games, they're usually a trap hand, but in pot limit games where implied odds are so important they can be fairly strong. When an A flops, there are a lot of hands out there that will give you action. Course, you need high potential to go with it as well...
23xx are horrid in limit, and meh in PL. In PL I'd play any 3 wheel cards in an un-raised pot.
The problem with 23 hands are the lack of high potential. with A2/A3 you have a powerful high card in the Ace (especially suited Aces), with 23 that is nonexistent (and likely in an opponents hand).
The 23 hands I like are:
23 + a pair 44-88
Besides the wrap straight draws and 2 pair potential that 2-6 hands gives youthere is also the 3/4s: 6's are important in O8 because they can give you 3/4s of huge pots when another player has a wheel (these pots are usually capped throughout in limit games)
44-88 pairs give you a chance at high, and a draw to low if you hit a set on the flop
Aim for the low. A234 gives one a great shot at that. The problem with high is outside of flopping a royal flush you rarely know if you have it, before the river at least. Also people chasing high hands can get really punished by no risk lows along the way so beware. So stay suited connected and low going towards A234.