How to say "you don't need to." In every language I know, the expressions for saying someone does not need to do something are often used to say they had better not do it.  Suppose I want to tell someone in an e-mail, in Chinese, that they do not need to do something and I really just mean they do not need to.  They can if they want.  What is a good way to say that without implying they should not do it? 

I am concerned specifically with the difference between "don't need to" and plain "don't".  I might want to say "You don't need to bring snacks to the party" without anyone thinking I mean "Don't bring snacks to the party."

In that case, I do not want to suggest the person not bring snacks.  It is fine if they bring snacks.  I would even like that.  But they are not required to bring snacks.
Generally 不用. 

e.g.你不用担心。 You don't need to worry/Don't worry.

你不用说。 You don't need to say./Needless to say....



不需要

e.g.你不需要这么早起床。 You don't need to get up so early.

你不需要药。 You don't need medicine. 



不必 (which is kind of odd or archaic)

e.g.你不必再谢他了。You don't need to thank him.



无须 (which is also very formal)

e.g.无须细说。No need to talk about the details.