When is dealing with someone else use poison arrows and then keep shooting (dont forget legendary card fot poison damage boost). Now thats a definite kill.
Do not hold the fire button when playing as Fernando. Your weapon deals damage over time after each hit.
Tapfire instead, so you can get value out of the DoT and refill your ammo in between shots.
Encountering Grover in long range spaces - don't PEEK around the corner.
Good Grover players throw axes preemptively and you can take a lot of damage. Use short sprints between cover. This way it's harder to predict where to aim.
In the start of a round, go near the objective but stay behind and wait for around 5 seconds, then use Scout to determine which way Skye will flank.
This also directly counters Stealth.
STUN STUN STUN... when with allies stunning anyone without a shield (excluding portable shield like tarvold's) can be your priority to help your teammates clear the point