Habits
Know what you have left
In one line: Before taking a duel, know how many abilities you have left.
Why
Many duels are lost reaching for an ability that is no longer there. Knowing it beforehand changes the choice: you wait for a teammate, change angle or play more carefully.
How to train it
At the start of every round and after every ability you use, look at the bar at the bottom and remind yourself what you still have.