IDIOMS

down pat

(idiomatic) Thoroughly practiced, rehearsed, or understood; mastered.

Example: 1913, Jack London, The Valley of the Moon, ch. 8:
  "She's got that Indian wrestlin' down pat, an' she's built for it."
2008 Oct. 9, Clifford Coonan, "The Bruce Lee legend," The Independent (UK) (retrieved 4 Nov 2008):
  He has the look of Bruce Lee down pat, with the same defiant expression and spare but muscled frame.