“I could always hit a home run, but if I try to do that all the time, maybe I not hit over.300. I am more valuable to my team hitting.330,.340, than I am swinging for home runs.”

As quoted by Les Biederman—who, not coincidentally, notes both Clemente's successful suppression of "the home run urge" and his ability to "hit for distance with the best" (the former earning the "unqualified praise of George Sisler")—in The Sporting News (June 1, 1960), p. 7
Baseball-related, <big><big>1960s</big></big>, <big>1960</big>

On his chances for a third consecutive NL batting title; as quoted and paraphrased in "Clemente Not Thinking of Batting Title" by Milton Richman, in The Cumberland Evening Times (Tuesday, March 15, 1966), p. 12
Baseball-related, <big><big>1960s</big></big>, <big>1966</big>
Context: “I never think about that before the season. Toward the end of the year I start thinking about it. Not before. I did it last year by just meeting the ball,” he said. “I didn’t swing hard at all. I think I’m going to do the same thing this year. We have two good hitters behind me now and I don’t have to swing so hard.” He means Donn Clendenon and Willie Stargell. The two hit a total of 41 homers to Clemente’s 10 last year. “They always say we need someone to hit home runs. We got some guys who can now. I don’t care for home runs. I showed ’em I could do it when I hit 23 in 1961. Home runs aren’t that important, though. Not to me, anyway.”

As quoted in “Clouter Clemente: Popular Buc; Rifle-Armed Flyhawk Aims At Second Bat Crown” by Les Biederman, in The Sporting News (September 5, 1964)
Baseball-related, <big><big>1960s</big></big>

Advice given to teammate Dick Stuart on April 7, 1959, as quoted in "The Scoreboard: Meet Ball, Homers Will Come, Clemente Assures Stuart" https://news.google.com/newspapers?id=IEIqAAAAIBAJ&sjid=aU4EAAAAIBAJ&pg=7149,2639076 by Les Biederman, in The Pittsburgh Press (Wednesday, April 8, 1959), p. 43
Baseball-related, <big><big>1950s</big></big>, <big>1959</big>

After hitting 2 home runs off Don Drysdale—the second and deciding one coming four pitches after being decked by Drysdale, presumably in response to the first—and driving in all 4 runs in a 4-1 Pirate win, as quoted in "Clemente's Bat Dumps Bums" https://news.google.com/newspapers?id=CYNPAAAAIBAJ&sjid=cSQEAAAAIBAJ&pg=5013%2C4959243 by Joe Carnicelli (UPI), in The Hendersonville Times-News (Monday, June 5, 1967); p. 9
Baseball-related, <big><big>1960s</big></big>, <big>1967</big>

As quoted in Baseball's Greatest Quotes (1982) by Kevin Nelson; reproduced in "Morning Briefing: Babe Ruth Was Not a Superstitious Man, Except on 714 Occasions," in The Los Angeles Times (March 1, 1982), p. D2
Unsourced variants:
Just one.Whenever I hit a home run, I make certain I touch all four bases.
I have only one superstition. I touch all the bases when I hit a home run.

From "'Keep Your Eye On the Ball'; No, Not Golf, It's Babe Ruth," http://archives.chicagotribune.com/1920/08/13/page/11/ by Ruth (as told to Pegler), in The Chicago Tribune (August 13, 1920), p. 11; reprinted as "How to Hit Home Runs," https://books.google.com/books?id=SAAlxi-0EZYC&pg=PA29&dq=%22I+always+swing%22+%22hit+or+miss+big%22&hl=en&sa=X&ved=0ahUKEwjZzNH7oM3QAhWJ4iYKHUCwC8wQ6AEIFDAA#v=onepage&q=%22I%20always%20swing%22%20%22hit%20or%20miss%20big%22&f=false in Playing the Game: My Early Years in Baseball, p. 29
Context: I always swing at the ball with all my might. I hit or miss big and when I miss I know it long before the umpire calls a strike on me, for every muscle in my back, shoulders and arms is groaning, "You missed it." And be­lieve me, it is no fun to miss a ball that hard. Once I put myself out of the game for a few days by a miss like that.

On hitting at Forbes Field; as quoted and paraphrased in "Clemente Unorthodox?" Well, He Gets Results"
Baseball-related, <big><big>1960s</big></big>

Source: Vampire Academy