Hello my name is Uberchancey, I am a Silver 5 player on NA, looking to share with you a secret gem of mine; Lee Sin Mid. At first many are skeptical of why you would want him in the mid lane, as was I, until you try him out. His W can dodge skillshots with a minimal amount of practice, and this is good because skillshots are everywhere on AP mids. His E is good for damage in engages and for clearing waves. Finally, what makes Lee Sin mid work: his Q. Q on to them, E them, punch 'em a few times and first blood is yours. I present to you my brief guide on how to play Lee in the mid lane.

Enjoy!

Cheese mids are mid laners that are unexpected/non-meta. Usually most cheese mids are typically found in the top lane (eg. Wukong, Pantheon, Riven) or in the jungle (eg. Lee Sin, Kha'Zix, Master Yi). Most are AD-Fighter type champions. The idea is to surprise/catch out your opponent because they don't understand the matchup.

Attack Damage reds are basically the only good option; always take these.
Armor yellows are good against an AD laner.
Health yellows are good against an AP laner
Flat Magic Resist blues are mandatory against an AP opponent; even if your enemy laner isn't they are still good for roaming.

Maxing Q first is basically the only viable option, as no other ability gives you the same utility as it does, whether you are building tank or bruiser. Max W second if you are building tank or if you are even/behind, getting the cooldown on your W reduced is surprisingly useful. Max E second if you are snowballing hard, because W does not provide any damage, just utility. If you buy a sightstone I would strongly reccomend maxing W to match for great ward-hopping potential.

Pros
Good Early Game
Can Shut Down Carries If Fed
Can Make The Enemy Mid Laner Useless
Can Build Asassin or Tank

Cons
Bad Scaling
Lose Lane=Lose Game
Ult Can Be Detrimental If Used Incorrectly
Not Great Against Other Cheese/Assassin Mids

Level 1

Assuming you started Sonic Wave you should start off by poking them down with your Q. In some matchups you may need to hold it back to last hit. I wouldn't reccomend engaging until you get level 2 or 3.

Level 2

At level 2 you start to get a power peak because you your Tempest, so you should capitalize this through calculated aggression it is unlikely you will be able to secure a kill without a jungle gank or a miracle.

Level 3

It's go time. Level three is Lee Sin's power peak, and he can duel most AP Mids at this point. Lee can duel some assassins, but be careful (Remember: Calculated Aggression) A good trick is to jump to the front of your creep wave and then Sonic Wave onto them.

Level 6

This is sort of the top of the slope for Lee Sin if you do not have any kills or are down a few kills I would strongly recommend building tanky. However, if you do have a few kills, things are about to get interesting for you. Try a few InSec* plays and maybe push the wave and roam around a bit.

*InSec is to Sonic Wave to someone, put a ward behind them, Safeguard to that ward, and then using dragons rage to knock them into your team. Practice these in custom games.

I am doubting that Lee Mid could have many applications in ranked play, as any mid laner who knows the game well will play safe and outscale you endgame. However in bronze/silver elo it is fine, but you will probably get hated on for breaking the meta in ranked.