Advice as Chip Leader in SNG's 4-Way

[obisponator]

As a SNG fiend, I find that my play when there are btw. 5-10 players at a table is fine, and I usually am either Chip Leader or 2nd in 10$ tournys. But when there are 4 players, the style of game immediatly shifts and people just play differently. Can anyone suggest a style of play, 4-way, as chip leader, and conversely, as low-stack? Thanks.