hedge one's bets 直译过来就是：“用树篱笆围住某人的赌注”，在口语中表示努力使自己做到万无一失，避免可能的损失(尤指不只把钱投在一种生意上)，所以这个习语的正确意思也就是：“躲避风险，留条后路”。因此，当美国人说"You'd better hedge your bets."时，他/她要表达的意思就是:"You should leave yourself a route to retreat."、"Leave yourself a way out."。
Jane: I've made up my mind and I'm gonna submit my resignation after work today.
Shirley: Are you serious? Well, you'd better hedge your bets. Don't fall out with the general manager while resigning.
①Don't rush to resign before contacting a new job.
②Don't displease everyone before you quit.
③Be sure to have your offer in hand before you resign.
④Keep in touch with coworkers you have worked with, for they may lend you a hand someday.
1. hedge vt. 用篱笆围住
Mr. Green began to hedge his courtyard in last year.
When I'm asked about this on occasion, I hedge the question too.
2. retreat vi. 退休，撤退
Retreating soldiers were dousing homes and shops with petrol and setting them on fire.
I believe people should live in houses that allow them to retreat from the harsh realities of life...
3. resignation n. 辞呈
Mr Morgan has offered his resignation and it has been accepted.
We haven't yet received his resignation.