don't

Somewhat sarcastic but usually good-natured advice used to criticise a person's degree of talent (especially in music or other performing arts), implying that they are unlikely to be successful.

Don't wait. Said cynically to suggest that what has just been mentioned is unlikely to happen soon or at all.

Don't overexert yourself (in doing something that does not require much effort).

Do not worry about it.

Used to introduce a guess at a fact or situation, as if forestalling the other speaker's utterance.