Smith was 5 of 7 from 3-point range. The junior guard has been the leading scorer in all three Cardinals victories and is averaging 21.3 points per game.
Blackshear started for the second consecutive game at small forward and made a career-high four 3-pointers for the Cardinals (3-0). He also grabbed a career-best six rebounds.
Senior center Gorgui Dieng added 11 points and nine rebounds and senior guard Peyton Siva matched a career high with 10 assists for the Cardinals, who shot 48 percent and hit 12 of 26 from 3-point range (46 percent).
Louisville entered the game averaging just 25 percent from 3-point range.
"People have been harping on our shooting the whole time," Cardinals guard Luke Hancock said, "but when we're getting open looks and running the floor as a team, we can make shots."
Louisville's defense held Miami (1-2) to 30 percent shooting and forced 19 turnovers.
Geovonie McKnight and Bill Edwards both scored seven points for the Redhawks.
Louisville started its third different lineup against Miami, beginning with Smith, Siva, Dieng, Chane Behanan and Blackshear while using Hancock as a reserve. The junior transfer from George Mason has struggled with his outside shot in the first two games, hitting just 3 of 19 coming in.
Part of coach Rick Pitino's objective was finding a good starting combination to take into the conclusion of the Battle 4 Atlantis tournament in the Bahamas.
Louisville starts Thursday with Northern Iowa but the tough field includes No. 9 Duke, No. 14 Missouri and No. 17 Memphis, while Stanford, VCU and Minnesota received votes.
His other goal was seeing whether his team could sustain energy from start to finish. Pitino was clearly concerned by his team's finish Thursday against Samford: despite winning by 26 and backing off the full-court press, Louisville was outscored 41-38 and allowed 50 percent shooting.
The Cardinals lineup got off to a good start. Eight of Louisville's first nine field goals were 3-pointers and the Cardinals finished the first half better from outside the arc (9 of 16) than inside (3 of 13).
They hit five during a 23-2 run that made it 33-12, including three in row by Smith en route to a 14-point half. Helping that stretch was Louisville's press that disrupted the Miami guards and thwarted the Redhawks' hopes of getting the ball inside.
Miami shot just 24 percent, committed nine turnovers and were outrebounded 22-17.
Louisville's 39-17 halftime lead grew to 49-17 as the Cardinals kept up the press and forced four turnovers leading to easy, shorter shots.
And the 3-pointers kept falling, including another by Smith while falling out of bounds that made it 57-20.
"We just get in the gym and work every day," freshman forward Montrezl Harrell said. "We told guys not to get their heads down, just keep shooting the ball and eventually it's going to go in."
Miami improved in the second half, but couldn't keep up with Louisville.
"Obviously they did a terrific job," Redhawks coach John Cooper said. "They were just so much better than we were. Of course, we couldn't score but I attribute most of that to their defense, certainly."