I decided to make this build after trying a whole bunch and just learning what works best for me and my team. RIOT decided to give me some sort of ISP issues and so the last 4 matches I played I got DC'd at least 3 times each game. Which is why I am here.

So naturally Lee Sin can be a bit squishy, so I gave him armor and magic resistance as well as attack damage in runes. Many other Sinners use armor pen. but I say otherwise as being a jungler you'll want the attack damage bonus for your skills, not to mention most of the creeps have little to no armor, so armor pen. is wasted on them.

As we have lots of attack damage in the runes and masteries we want to take advantage of that and start with Tempest/Cripple. Also the slow helps out and the AoE damage for jungling is tasty. We then want Safeguard/Iron Will so we have some extra life steal/spell vamp and a little shield. Useful for the track I'll take you on for Red. You'll then want to spam up Sonic Wave/Resonating Strike for max damage, boosting your ability to jump the enemy.

Wolves, pot after killing big wolf.
Wraiths, pot after killing big wraith. (Level 2)
Red, use W first, then E, then for the second W, when your Iron Will is up hit the big fella with your Smite for some extra healing.

MAKE USE OF YOUR PASSIVE. I've seen some people play Lee Sin and they just starve his energy and well... need I say more.

After you have Red buff, check bottom and middle lanes to see if the enemy is either pushing hard or the team needs a hand to get that last battle initiated for a kill or two.

At this stage you'll be level 3 or 4, return to jungle and continue killing small spawns until your assistance is required. Make sure you give the main caster the Blue buff, pick the one with either the highest kills or the biggest trouble with mana, like a Ziggs or Lux, it's very hepful at this stage in the game.

Once you are about level 7 or 8 you'll only be going into the jungle on the way from one lane to another. Help out with pushing and killing towers quickly before the enemy pulls some maneuver on that poor Ashe soloing a tower.

From here on, laning phase is over, as is the jungling phase. But grab the Dragon and Buffs as much as possible, as these are quite powerful for the whole team.

Although you have a beast amount of armor and hp, you are not the TANK, you are a tanky dps. It is your job to roundhouse kick the casters and healers at the back of their team straight through the middle. Although, you should rarely initiate the team battles. Taking out a strong caster or healer can severely cripple their team fight. Twitch is also a good target as they always spam attack speed, and can be freaking powerful.

Try to save W for escape, unless it looks like you won't need to be running soon, in which case dodge an attack and shield an ally at the same time. Although this skill is only really good for mobility until late game, when a 200 hp shield means almost nothing anyway. It can save an ally from that annoying ignite or poison post-battle.

When you have gotten your Atma's you may notice a particular player or two on their team is racking up some attack speed or attack damage, like a Twitch, Tryndamere, Master Yi etc. If you think it is getting quite difficult to take out these sorts of champs even in massive team battles, maybe get a Thornmail or Guardian Angel before the Trinity Force and instead of the Hexdrinker. Unless ability power is a bastard too, in which case stuff the Trinity and Hex it up.

If you notice the other team's average level is greater than your level, it may be wise to spot a lane with a significant enemy minion population and Farm that hard.

Ward with your Lantern at either the little bush near Drag or the little bush near Baron, depending on where the game is at. This will also help mid in knowing if they are about to be jumped.

This is my first build so let me know how I went. And don't be a *** and say I should get Infinity Edge or Bloodthirster. W + Lantern gives enough life steal.