Hi! I'm Faraz, and I'm here to show you how to play Illaoi jungle!
I mainly play top and jungle, and this build will show you how to play Illaoi in the jungle :)
NOTE: this guide is for low elo/normals only because Illaoi is not designed to be a jungler and I'm not a high elo player either.

You can start bot-side jungle or top-side. It's your choice.
Set up 2 tentacles near the monsters and start W. then take Q first and try not to die on your first clear. You can't really pull up good ganks before level 6, so focus on farming and buy your first Items. However, You can gank lanes when you have your passive's cooldown close to 0, so you go in and spawn a tentacle near the enemy, take their soul (E) and start fighting. Try to hit both the actual enemy and their soul with your Q. and if you don't have Q, attack the enemy instead of the soul. unless It's really low hp and u wanna trigger the slow and auto tentacle spawn...

this is where Illaoi shines. After you get your first 2 or 3 Items, you can 1v2 people if you kite them into your tentacles and start smashing them! esp in low elo where players aren't experienced enough. But don't forget about farming. Illaoi's clears are so fast in mid game so take advantage of that.
Also, you can solo drakes. set up 2 tentacles in the dragon pit and keep W'ing the drake. and If they come for you, you can pull their soul, ulti them, and destroy everything. your tentacles also probably damage the drake when trying to hit champions.
Remember: ALWAYS fight with at least one safe tentacle near you.
Illaoi's super late game(45 min+) isn't as good as her mid game. most of the champions outscale you but you can pull up good moves even in that stage.
*** *** *** ***
If you're behind, just try to play safe and farm back into the game. Illaoi is really good when behind :))) they don't expect that much dmg from you when you're behind. so don't be afraid. as long as you have at least 1 tentacle and u hit your E, you can press R and get a pentakill. your welcome.(CAUTION: works only into noobs or generally braindead enemies)

Update: Illaoi seems to be pretty damn strong in the current meta [10.25], just don't play her in the jungle if u wanna climb. this is a fun build you can try to troll your enemies by getting a penta just by hitting E + R combo.

and by the way, her best skin is the new cosmic one, it looks dope.
skin tier list: Void(OK), Resistance(cool), Cosmic(daaaaamn dude).

---

===================================================================================

So here it is! Hope you enjoyed; I wrote important stuff in the notes of everything in this build so check them out and try this build as a fun build! Feel free to rate and ask questions. enjoy!