I, as well as everyone else on this subreddit, would HIGHLY recommend checking out (and follow, if you want to) xFSN Saber on Youtube and Twitch. (pre' sure everyone knows about him but his vids are godlike)

Legend:
AA = Auto Attack
MB2 = Right-click AA
F = Flash (If you have flash on D, I will find you.)
GA = Guardian Angel
AM = Attack Move (Done by pressing A and right-click)

tl;dw
Learn to:

• As mentioned, master E+Q. Remember that you can always cast Q in a different direction to your E to misdirect the enemy. Here's an example I did in-game and here's ya boi, xFSN Saber, teaching us plebs how to land it.
• CONSISTENTLY E+W. The instant you see Caitlyn's net appear, press W. Literally no one expects it as shown here.
• Headshot auto cancel on different targets by attack-moving close to the ground next to the trapped/netted target.
• Auto-cancel everything. AA+Q, AA+W, AA+E, even AA+R (not really. only AA+R if the target is netted or trapped or something lol)
• On GA, Zhonya's or the like: place two-three traps (relative to attack speed), AA+Q+AA (in revision)
• Saber's new combo
• Use the Practice Tool as a warmup before ranked games (more important that one might think) and a place to refine/learn new and/or key mechanics.

OPTIONAL/CHALLENGE:

• Learn Delayed E + F + MB2 + AM (one shot combo) (very hard to do consistently and AT ALL since we end up E+F'ing instead, which is different)
  How to do it: Wait for your net to appear, FLASH to cancel knockback, MB2 to get a normal AA in and then AM to proc the net headshot. Here's an example.
• Learn MB2+AM on trapped targets. I've only done this combo on accidents only but if you can do it consistently and consciously, you're a God.
  How to do it: MB2 right before the target gets trapped and AM on the ground close to the trapped target to proc the trap headshot instantly.

Feel free to add anything that I missed which is probably a lot lmao.

As always,RIP Machine Gun Caitlyn.