Omaha is different than most games. Most say that in holdem, aggression wins pots most often because its hard to make a superior hand.
I dont advice this in omaha, well in heads up omaha you raise pretty much 100% of buttons but in 6max, no pls.
In 6 max omaha cash games you are looking to make nut nut. Basically nut flushes and high straights. You can achieve this by opening with a solid range of hands, so it is smart to not open with low cards, low 2 suited, small pairs, those are really - ev hands. You will lose the most money drawing to weak flushes and low straights and low sets. But like holdem, omaha depends on the opponent as well, if you have a villian opening 80% of his range every hand then there is a good chance a 9 high flush is perfectly fine against him. Against a tigher player who is opening 20% of pots a 9 high flush might be... not so sweet.
Another thing is trips/2 pair/set type hands. Ok, well.... you want to make top set, or middle set is ok sometimes, again it depends on your opponents opening range. 2 pair is in general not a strong omaha hand, its fckin amazing if you fill up, if you dont fill its often going to get outdrawn if you do not end the hand as soon as possible. If you are playing a multiway pot with 2 pair they are going to have so many outs to beat you unless you get very lucky/fill you are toast.
Aiming to make very good hands in omaha is generally the right strategy, as winning is often about getting people to get all their money in with an inferior draw or a smaller set/2pair.