So i just got him, and it's tough to sustain in the jungle, I just played a game where I got a leash for Wraiths and Red, and almost died getting wolves, I even built Cloth Armor instead of Hunter's Machete. Anyway I get my abilities, E-Q-W, and then build E from there, but why am I so squishy?

Masteries: (I'm only level 22) 6-13-3

I only have a few average runes, but is there any technique or something i should do?

I know to do Ability-Attack-Attack-Ability

Any tips to survive easier? I don't have any problems with Nocturne, Nunu, or Trundle, even without a leash for them

Well i hope u at least have armor runes....no runes makes jungling super hard

ya well people keep telling me that im "too low a level to buy runes" i kinda believed them too, i guess i'll start by getting some armor

you can buy runes starting from level 20, just make sure they are the tier 3 ones

Armor Runes help a ton...Minion Damage Reduction and the rammus armor thing help also. Maxing w gives you great sustain in the jungle at the cost of ganking power of his q.

You should change your masteries to 1-21-0 for now, you need to be tankier with jungle lee anyways. You can point the 1 point in Summoners wraith if you take exhaust or 1 in Butcher if you dont. The 21 in defensive tree is up to you. Personally I would go as follows:
4-Durability
1- Vet Scar
2- Tough Skin
1- Bladed Armor
3- Hardiness
Either 3- in Resistance or 2 in Unyielding and 1 in Block
3- Tenacious
3- Juggernaut
1- Honor guard

If nothing else you need to drop IP to get Armour Yellow Runes. They are used on almost every single standard rune page.

Ok thanks for the Masteries tips, and I decided not to buy anymore champs until I get all my available armor masteries

Any other tips?

get wriggles start hunter machete get armor masteries get armor runes

your combo should be W-AA-W-E-AA-AA-E-AA-Q-AA-AA-Q-AA-AA

Also another thing with Lee sin is Learn to gank with your W then E Q don't initiate with your Q