How do you avoid being too "clownish"?

Where's the line when it comes to humor? On one hand, I want to give zero fucks and be energetic, silly, and self-deprecating in a way that amuses me, but on the other hand, I get the feeling that I get pegged too often as a "screwball" and ladies don't see that trait as particularly attractive.

How do we find a happy medium? How do you distinguish between funny and charming and downright clownish?