I dont think question was about omaha, so lets consider texas
Always consider possible range of you opponent. You can quite neglect his pocket pairs, its just too rare to hit full house. So villain needs those 2 cards you see on board. Could he enter game with that?
- if you are deep, try to get to showdown for reasonable price. Usually its not good to go all-in, you will mostly get called only with better hands. I much rather let opponent to go all-in, then call. Its the same result if he has nuts, but much more profit when he doesnt.
- if you are not deep, what is there more to wait? You expect to get better cards then flush with last couple of blinds? You should be very sure about fold (good read, bubble, or some other reason). If you are not sure, shove and hope.