Habits
Check the minimap after every kill and death
In one line: After every kill or death, a glance at the minimap.
Why
Every kill changes the situation: where your teammates are now, where enemies are coming from, which area is open. The minimap tells you in a second.
How to train it
For one game, every time a kill appears in the feed, look at the minimap. After a few games you will do it on your own.