The Brewers prospect pitched a three-hitter for his second straight complete game Friday as the Timber Rattlers blanked the Clinton LumberKings, 5-0, in the first game of a doubleheader.
Miller (1-2), who had an extra day's rest following Thursday's rainout, walked one and struck out six.
"You have to get ahead of guys and pound the zone," he said. "That's what I learned tonight. You have to remember that you are in charge out there. Taking the pressure off yourself and putting it on the hitters is the key."
Miller is the third Minor Leaguer to toss two complete games this season and the first Midwest League pitcher to pitch a complete-game shutout.
The 22-year-old right-hander gave up a leadoff single in the first inning to Shaver Hansen, but Julio Morban grounded into a double play and Tim Morris struck out.
Miller retired the side in order in the second and the Wisconsin defense helped bail him out in the third.
Marcus Littlewood drew a leadoff walk and Steven Baron singled, but Littlewood was thrown out at third base by center fielder Reggie Keen. Baron was nailed trying to steal second and Miller got through the inning unscathed.
"My defense was big behind me," the 2010 fifth-round Draft pick said. "Reggie threw out the guy going first to third and right after that Tyler Roberts threw the runner out at second. Me and Tyler were clicking all night long."
Miller, a Pioneer League postseason All-Star last year, faced just one batter over the minimum the rest of the way, yielding a leadoff double in the fifth to Mickey Wiswall.
"We had a lot of success throwing the fastball tonight," the University of Michigan product said. "They were a predominantly left-handed lineup, so we were going hard away and then changing the pace.
"Once we got ahead, we could use the changeup in any count and that helped us get a lot of ground balls."
Miller, who lowered his ERA to 4.43, had a rough introduction to the Midwest League. He gave up five runs on four hits and five walks over four innings in his season debut on April 8, then surrendered four runs on four hits and three walks over 5 1/3 frames in his second start.
Last time out, Miller allowed three runs -- two earned -- on three hits and three walks over six innings.
"I've made a few changes to my mechanics and my delivery, and that has started to work," he explained. "I was making things too complicated, but each start it is coming around.
"My delivery is becoming more comfortable, I am keeping my weight back and getting a good angle and tilt. I'm not over-thinking things now."