"Practice doesn't make perfect; perfect…

“Practice makes perfect” is a proverb from at least 1730, frequently used in sports and other fields.

The popular variation—“Practice doesn’t make perfect; perfect practice makes perfect”—has been cited in print since at least 1923. The saying is frequently (and incorrectly) credited to football coach Vince Lombardi (1913-1970).

The Free Dictionary
Practice makes perfect.
Prov. Cliché Doing something over and over again is the only way to learn to do it well.

ThinkExist.com
“Practice does not make perfect. Only perfect practice makes perfect.”
. Vince Lombardi quotes (American Football Coach, national symbol of single-minded determination to win.1913-1970)

Google Books
The Yale Book of Quotations
Edited by Fred R. Shapiro
New Haven, CT: Yale University Press
2006
Pg. 618 (Proverbs):
“Practice makes perfect.”
John Adams, Diary (1761)

Google Books
August 1730, The Present State of the Republick of Letters by Joh. Petr. Biester, pg. 88:
... for practice makes perfect in all business, arts, and sciences whatsoever.

Google Books
Psychology and Self-Development
By Henry Eastman Bennett
New York, NY: Ginn and Co.
1923
Pg, 49:
Let us revise the old saw to read Only perfect practice makes perfect.

Google Books
Orientation for College Freshmen;
Adaptation to college life, vocations, and citizenship
By Ernest William Hawkes and Ralph Leslie Johns
New York, NY: Ronald Press
1929
Pg. 200:
Only perfect practice makes perfect, or nearly perfect practice tends to improve until perfection is reached.

27 February 1930 The Sun-Herald (Lime Springs, IA), “News and Gossip of Lime Springs Public Schools,” pg. 1, col. 5:
There is a saying that “Practice makes perfect,” but we have been taught differently. We believe that only “Perfect practice makes perfect.”

Google Books
Listening and Speaking:
A guide to effective oral communication, Issue 5
By Ralph G. Nichols and Thomas R. Lewis
Dubuque, IA: W.C. Brown
1954
Pg. 144:
As someone has wisely said “Practice does not make perfect; perfect practice makes perfect.”

14 January 1979, Galveston (TX) Daily News, “O’Connell Athletes Feted” by Vince Stiglich Jr., pg. 1C, col. 8:
He (Jim Yarbrough—ed.) also said that the adage “Practice makes perfect” was not enough to make a winner but that “Perfect practice makes perfect” generates top flight performances.

Sports Illustrated
September 11, 1995
A Native Son’s Thoughts (Many of Them Heretical) About Baltimore (Which Isn’t What It Used to Be), Baseball (Which Isn’t What It Used to Be) and the Steadfast Perfection of Cal Ripken Jr. (Which Is Ever Unchanging, Fairly Complicated and Truly Something to Behold)
Richard Ben Cramer
(...)
See, Cal’s dad, who taught him, has these sayings—said them all a million times—like: If you want to play the game properly, you have to get ready to play.

Or there’s this one:

You have to know what you want to do before you can do it.

And even more often, there’s this one:

Practice doesn’t make perfect. PERFECT practice makes perfect.