At matchpoints, generally it’s a winning strategy to risk going down when you are in a contract that you expect to be reached at many tables, and when you think you will make an overtrick more often than not. At IMPs, it’s almost always a winning strategy to sacrifice possible overtricks in order to make your contract.
At matchpoints, generally when your side has most of the high cards, it’s a winning strategy to bid a game when the game will make, more often than not. At IMPs, generally, when you’re vulnerable it’s a winning strategy to bid the thin games that you should avoid at matchpoints.
At matchpoints, generally it’s a winning strategy not to allow the opponents to declare at the two level when they have a fit. At IMPs, generally it’s better to let them play in that contract unless you think you are at least somewhat likely to make your own contract.