If you can get your first pool party of the season even close to that of a high-rolling, champagne-spraying hip-hopper, you know you're doing summer right. There's cool dudes, hot ladies, cold booze, grilled burgers and, if you're P Diddy, a jet ski for absolutely no reason whatsoever. But there's also the style. Rappers are well versed in dressing for the poolside, given the sheer amount of music videos they like to shoot there. Here are five lifesaving style tips from some of the best…