Always be firing, be it at an enemy hero or a shield, unless you are repositioning, you should be firing
Fire in long bursts, 5-7 bullets, to keep accuracy without sacrificing dps
In 1v1s, drop your biotic field as soon as possible, one, for more sustain, and it will interfere with your dps
Prioritize Pharah PLS
When firing your helix rocket, aim at the ground beneath your target, if you miss, at least you get splash damage
To add a little bit of style, you can learn 76's rocket jump spots