"Do not eat in bed!"
Translation:Nicht im Bett essen!
Here are the versions of the translation, which a native speaker gave me:
If you are talking to one person (Du): Iss nicht im Bett!
If you are talking to two people (ihr): Esst nicht im Bett!
If you are using the polite form (Sie): Essen Sie nicht im Bett!
If you are stating it as a general rule, the two versions mentioned previously: Nicht im Bett essen! and Im Bett nicht essen!
And I sincerely hope that there are not too many more versions because I am already feeling dizzy...