1. Play Titanfall 2
As bizarre as it sounds, one of the most effective things you can do to get better at Apex Legends is go play Titanfall 2 - Respawn's other shooter, and one of the best FPSs of the generation overall.
Firing yourself into Titanfall lets you experiment with Respawn's physics-heavy sense of movement on a grander scale, and you'll get better acquainted with monitoring various angles while staying on the move, factoring slides and wall-runs into combat, too.
Speaking of which, knowing how to maximise your movement options while keeping a bead on an enemy is something you can only get down while in constant encounters. Being a Battle Royale, you'll have minutes of combat every now and then, whereas learning to master Titanfall 2 only makes you approach the closing rounds of an Apex Legends duel with confidence and a steady hand.
Also, Titanfall 2 simply needs the love, as being released slap-bang in the middle of Call of Duty AND Battlefield all but killed its chances back in 2016, here's hoping Apex Legends sees people trying out the "full" experience for such an immaculate gameplay model.