Tell your team that you can't be alone in a lane
Roam the map in search of targets
Don't try to take down tanks with more than half health
You can use Pinning Shot first to make the aim of your Snipe easier
Your decoy can activate the slow of Pinning Shot right from the get-go
Use your Holo Decoy to tank tower shots and kill opponents even behind their walls!
Aim the Precision Strike a tiny bit ahead of your opponents if they're moving
After level 7 remember to move between your auto-attacks until you see the circle around Nova's gun, that way you can chase better