I assume we are talking about Omaha Hi, not Hi/Low. And PLO. It's a wild game and a lot of fun, especially if you like seeing/getting big big hands.
I kinda prefer double suited wrap hands. Mid to high. A wrap hand is, say, 789T or JKQA or some such. On the flop, you know if you are in the ballpark and, if not, it's easy to fold. If you are, you can possibly have both a flush and straight draw, if you haven't made it already. Beware of making a non-nut flush as always -- but the beauty of the mid-range wrap is that you can sometimes land that lovely straight flush. WIth a non-nut flush, bet at it but be prepared to fold if someone comes over the top of your bet. 90% of the time, he has the nut.
Beware of any time the board doubles, though. Generally, someone has made a boat, unless the board is all low cards. Don't go all wild with a flopped straight either -- it's often dead meat by the river. Do bet it, though. Make the other guy(s) have to get lucky. No free cards.
AA and KK can be fine, if you get
heads up with someone else preflop. (The other player will likely have whichever one you do not have. Expect it.) It tends to be a race.
The other way to play AA is to put in a preflop raise and, if an A comes, bet the heck out of it. Check-raising is very powerful in PLO.
On the whole, any hand where you have a made hand of some sort (set or 2 pair at a minimum on the flop),
plus a good draw, is a hand that is worth the risk of sticking with. You need room to improve. It's very very rare to win a PLO hand with one pair. (Which is why playing AA hard can be so problematic.)
PLO often requires you to stick with hands that are not there yet, so you need heart and guts more than anything else. And a sufficient
bankroll. You can lose a lot more buy ins in this game than in NLHE, because of the prevalence of good hands and pot-sized bets. But when you are running well, you can run very well indeed.
Good luck out there.