The Light Blues missed the chance to move 22 points clear at the top of the Irn-Bru Third Division on Saturday after David Gray's last-gasp strike snatched a 1-1 draw for Montrose at Ibrox.
Templeton accepts that the team performed poorly at both ends of the pitch and is hoping for a much improved display when they travel to Tannadice next week for the William Hill Scottish Cup fifth-round tie.
"If we do get chances like we did in this game, we have to take them," he said.
"Dundee United are a strong side and we can't give them any chances near the end of the game because they will punish us.
"They've got some very good players, such as Johnny Russell, and if we give him any chances, I'm pretty sure he will punish us.
"We will have to be a lot better defensively and make sure we cut out our mistakes."