I would guess that you try to exert too much control. The kind of "sloppiness" that's useful for creativity is about letting things go.
Meditation might help.
As you are female, dancing a partner dance where you have to follow and can't control everything might be useful. Letting go of trying to control is lesson 101 for a lot of woman who pick up Salsa dancing.
As a lead, you learn that you aren't really controlling much of anything in Salsa either. You're setting boundary conditions; follows have a fascinating way of exploring the space of those boundaries in ways you often don't expect.
But I'm guessing that you've hit on the right direction of interpretation of sloppiness as letting go of control. I'd extend that to too much self conscious control. Great art, and particularly great dancing, is finding a clear intention and a method of focusing your discursive consciousness and voluntary attention that harnesse...
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