"It's about taking those opportunities that come along and scoring some tries. If we'd done that against the Hurricanes, we wouldn't have been under pressure at the end."
The Highlanders have yet to earn a four-try bonus point but no team in the competition is crossing the tryline regularly as defence dominates.
Mackintosh said teams were concentrating on defence, and not conceding penalties.
"The higher the level of rugby, the bigger the tackles then the more pressure they put you under. There's a bit of a theme coming through in the way teams are fanning out and not really attacking the breakdown.
"That's a little bit different from us. Teams like to defend for a long period of time and back themselves to not be broken."
The Brumbies were picked by many to be the cellar-dwellers of the competition after a cleanout of players from last year.
But they started the competition with two wins before falling to the Chiefs last week.
The loss was a close-run thing and previewed what the Highlanders can expect in Canberra tonight.
World Cup-winning coach Jake White has immediately stamped his mark on the side - with suffocating defence, and forwards crashing the ball up. They don't give the ball away much, either.
Mackintosh said the Brumbies' patience with the ball meant his side would be in for a battle up front.
"They look to play a lot of field position and do not like playing in their own half. They are very patient with the ball, a lot of direct runners off the nine, and good with the ball in hand in close quarters."
The Highlanders were messy in their lineout last week and without the injured Adam Thomson, someone else will have to come forward to win ball.
Much is expected of English international James Haskell in his first start and Andrew Hore is sure to enjoy locking horns with Stephen Moore.
The Highlanders need to get their gamebreakers involved more tonight and stay disciplined in defence.
The Highlanders don't have a great record in Canberra, the scene of their biggest loss in 1996, and they haven't won there since 2006.
The match is to be refereed by South African Lourens van der Merwe, making his debut at this level.
Highlanders v ACT
Canberra Stadium, tonight, 9.40
Ben Smith
Kade Poki
Tamati Ellison
Shaun Treeby
Hosea Gear
Colin Slade
Aaron Smith
Nasi Manu
Doug Tietjens
James Haskell
Culum Retallick
Josh Bekhuis
Chris King
Andrew Hore
J. Mackintosh (c)
Jason Rutledge, Bronson Murray, Nick Crosswell, Elliot Dixon, Jimmy Cowan, Chris Noakes, Buxton Popali'i.
Jesse Mogg
Joe Tomane
Andrew Smith
Pat McCabe
Henry Speight
Christian Lealiifano
Nic White
Ben Mowen (c)
Michael Hooper
Peter Kimlin
Sam Carter
Leon Power
Dan Palmer
Stephen Moore
Ben Alexander
Anthony Hegarty, Ruaidhri Murphy, Scott Fardy, Ita Vaea, Ian Prior, Zack Holmes, Tevita Kuridrani.