Why did I put this build on Mobafire?
I want to know what I could do better with this build, so comments would be nice.
Also, the builds that already exist, don't appeal to me that much.

I takeExhaust, because there are always enemies who try to run, even if you're Lee Sin. So you Exhaust them, ofcourse you have improved Exhaust, and you take the kill.
Exhaust is also a god spell if you're trying to get away from people. The Exhausted Champion won't be able to outrun you, except when you've got a Ulting Master Yi after you, but then you just turn around and kick his ***.

I also takeGhost. This is a good spell to chase, flee or get to the place you want to be.

Lee Sin is an AD Champion, so I prefer to take 21-9-0. Why don't takeHaste, while I do use ghost? BecauseNimbleness is much more useful. With the Evasion masterie, dodge runes, and Ninja Tabi, you'll eventually have near 20% dodge chance, so nimbleness will activate a lot. Ghost will still be useful, and that little bit extra movement speed is often gained more with nimbleness, en those 1.5 seconds more are a good cost for the Nimbleness.

I always takeSonic Wave/Resonating Strike first, as its a good last hitter, and a good harrassing skill. Next, I want my other skills on lvl 1, which one first will be situational. If your getting harrassed much, you takeSafeguard/Iron Will, if not, you takeTempest/Cripple, for more damage and better farming possibilities.
Next max Sonic Wave/Resonating Strike. The second max is also situational, if you need survivability, max Safeguard/Iron Will second, if you need more damage or don't need the survivability, max Tempest/Cripple second.
Ofcourse takeDragon's Rage at lvl 6, 11 and 16!

I takeArmor Penetration Marks and Armor PenetrationQuintessences. With this you'll do a lot more damage, especially early game.
I takeDodge Seals. Nimbleness will come to good use with these seals. If you don't take Dodge Seals, don't take nimbleness, but Haste instead!!
I take FlatCooldown Reduction glyphs. CDR is more usefull early game, because you rely more on 1 skill, Sonic Wave/Resonating Strike, and the faster you can use it again, the better.

I start with theCloth Armor and 2Health pots. This way I can take Ninja Tabi quick, and be less squishy early game.
Next I takeNinja Tabi. The dodge chance is really nice for your Nimbleness. Also they aren't so expensive so you can get on to you AD, and do the Damage.
When the enemy team has a lot of CC, like slows and stuns, or they ar AP heavy (goes together a lot)Mercury Treads are your best friends! They cost a bit more, but it's money well spent!
I actually take Mercury Treads more then Ninja Tabi, because of the enemy team. With Mercury Treads, it is more useful to take Haste instead of Nimbleness. I still take Nimbleness however, because it will be epic when you can take Ninja Tabi!
When you'll take the Mercury Treads, your starting item should be Null-magic Mantle!

I Really likeHexdrinker. It gives good AD and it gives some MR which you'll need, if you don't want to die quickly. The shield also gives you a chance to survive when being focused in team fights. When in batlle with some AP nukers, Hexdrinker's shield is quite unexpected and can give you the edge and take the kills.
When the other team is AD heavy, however, don't take it, its wasted money.

Next I go forTrinity Force. This item is a must for Lee Sin. Start withSheen, so after a skill, you'll do a lot more damage, don't forget to time your skills well!!
Go forPhage afterwards for the AD and the slow.

Next I likeMadred's Bloodrazor. It gives good damage, and quite a bit Attack Speed, which you really need at that time. Don't go rushing Infinity edge, it's a wonderful item, but without the AS, you'll still be hoping for the last hits to take the kills, with Madred's, the kill is almost definitely yours!

Now you can takeInfinity Edge! When you got it, it's Pentakilltime!!

Last item is situational. I putBlack Cleaver there, because it gives some more AS and AD. ButBloodthirster is always nice, and other high AD items are also a good choice.

In the laning fase, try to last hit minions much. Lee Sin is early game not a good farmer, so you will really want those last hits. Still don't forget to harrass now and then, and when the time is right, take the kill. For this, Sonic Wave will do the first damage, they try to run, you do your Resonating Strike, when needed a few auto-attacks, and take your precious money.
When needed, heal with your Iron Will, which will give you some Life Steal and Spell Vamp.
Ofcourse you are a bit dependent from your laning partner to take the kills, but Lee Sin can solo enemies early game quite well. So don't hesitate when you think you can take the kill but your alone, or you partner is too far away!

Mid game is the hardest part with Lee Sin. He dies easy, will be focused a lot, especially when you took a lot of kills early game, and his damage isn't as Epic as at the start.

The most important thing to do is, support. Try to save allied champions with your Safeguard, and slow the chasing champs with cripple. Don't try to die yourself either. When possible, take the kill, but don't go chasing on your own, when enemy champions are missing. You'll probably be ganked, raped and thrown in the bushes to cry for help...

However, if you get through this fase, with a few kills, and little deaths, your back in the game!!

When you're overfeeded early game, you don't have to worry midgame. Just do your thing, be Lee Sin, the Blind Monk!

Lategame, Lee Sin is back!
You do a lot of damage, don't die easy, especially with your Iron Will (don't forget this, it's critical to survive when being focused!).

Always start with your Sonic Wave, then Resonating Strike, Slow them with Cripple (some damage first with Tempest ofcourse) and put your shield on for the flurry. Ult them when necessary.

A good way to use your ult is to get behind the enemy team (prefer unnoticed) and roundhouse kick the champion most in the back against all the others. It does Excellent damage, and your team can hop in and do epic damage. Then you jump in with your Sonic Wave/Resonating Strike and take the Pentakill! :)

A very critical point with Lee Sin, is his passive,Flurry.
Use this as much as possible. You'll get a lot of AS and also quite a bit energy with the next two hits after each skill!
So space out your skills. After a skill, make two AA hits, then the next skill. This will also work perfectly with Sheen, the next hit after a skill will do 100% more damage.

When attacking turrents, don't forget your passive either. Even when there are no minions or enemies near, just fire your Sonic Wave, shield yourself, or use Tempest. You'll attack a lot faster, and turrets will go down a lot easier.

Please comment so I can improve my build!
When you disagree with me, tell me why. :)