I know that you have decided to leave the club, but please reconsider.我知道你已决定退出俱乐部了，不过请你三思而行。I'd think twice about/before doing that if I were you.如果我是你，做那件事我会三思而行。If you're planning to invest in your friend's company, I advise you to look before you leap.如果你打算投资朋友的公司，我劝你要三思而行。