Despite picking up their first win of the season against Charlton Athletic, Mowbray feels more goals are needed and conceded his team could have lost.
"We controlled the game for long spells but we've just got to make sure we put the ball in the net more often because it could easily have gone the other way today," he is quoted as saying on BBC Sport.
"We've been letting ourselves down in both boxes in our opening two matches and we put in a much better display. Now we have to try to build some momentum from this and move forward."
Boro face Blackpool at home next in the league.