How do you say "help yourself"?

Question

I would like to post a sign in my classroom that says "help yourself" to indicate that people may take anything from the table they would like. What would be the proper way to say this?

Answer 1

Feliz suggested the formal option (usted),

being friends with sb. you'd use

sírvete

(tú)

Answer 2

I think you can say: íSírvase Usted!= Help yourself

I hope this helps

Answer 3

What are the items? If it is food, then I agree, the verb servir would be best, but if it is books/other school items, how about "tomar?"

Tomen (Uds.) lo que quieran.

I think the plural use is better, because you are addressing the issue to more than one person, i.e: "help yourselves".