"Take a good rest" or "Get some rest" are both common ways to say "好好休息" in Engpsh. Here are some other options:

Get some rest and relaxation
Get some well-deserved rest
Take a break and rest up
Take it easy and rest
Relax and recharge

All of these phrases convey the idea of taking some time to rest and relax in order to feel refreshed and rejuvenated.