Rebuy tournaments tend to play very loose-agressive during the rebuy period. You have to expect a lot of varience during this period (even if you play tight, the other players will chase draws and occasionally hit them). You need to go in with the expectation of taking a rebuy at the very beginning (if the tourny is structured that way) and probably rebuy after one bust out. While this early action is fast and loose, it's pretty good to take advantage of it.....this means lowering your starting requirements and splashing around a bit. This has been my experience....others choose the more conservative approach which allow less investment but also lowers the number of eventual cashes.