You'd better not waste any more of your time.

你最好别再浪费你的时间了。

You'd better not have your hair cut during the Spring Festival month.

你最好不要在春节月期间理发。

She won't listen to reason when she's angry, so you'd better not provoke her.

她在生气的时候不可理喻，你最好别惹她。

You'd better not hang out after school without telling your parents.

放学后你最好不要没告诉父母就出去玩。

You'd better not do sth.

你最好不要做……

No. You'd better not do anything.

不要。你最好什么也不要做。

You'd better not give up halfway!

你最好不要半途而废！

You'd better not count on a raise.

你最好不要指望调薪。

You'd better not take a bath today.

你今天就不要洗澡了。

You'd better not invent that, Danny!

你最好不要发明那个，丹尼！