So first of all, i want to apologize for my English, I'm not speaking it as my primary. So, the reason I wanted to make a build, is to give you other aspects of building lee. There are many similar guides, which almost all include same items and style. The key point in this style, is to remain safe in start, but hit back if people try to harass you! Well, I'm a man of few words, so let's get busy shall we?

Well. This is what changes the most from other builds. Usually they say, you should get HP or armor for survivability, but i disagree. Before you get sheen, you must be very careful when harassing people, cuz your damage output ain't so significant. AND WHAT is most important in harassing, you must not just autoattack minions to get the kills.I'll explain later on how to harass properly. So Sheen, when you get this item, you are basically undefeatable 1v1, cuz of the awesome skills. After EVERY TIME you use your SKILL, or theSECOND PART of the skill, you will get the sheen bonus. Your damage output will be in such level, that almost no1 can take it. After getting sheen, I usually get more damage causing them to start prayin' for their lord.
Depending on situation, you should take primarily get The Bloodthirster first, and starting from Vampiric Scepter first. Thanks to Sheen, farming will be usually easy in this point, because most people know how hard you hit back if they charge on you. Sometimes if facing Tanks, or so much harashment, that you cant farm enough money, you should go for Last whisper first. After these items, you shud be quite overpowered on other champions, so you can start building whatever needed.

I've tried also flat hp and flat armor runes, but I've found this better for my quite offensive build. Att speed and armor pen gives a good boost for your damage, and after lvl 4, you shud do some serious damage. Enough said.

Okay, I'll do this quick. I assume people have played Lee Sin, or watched some of the most popular guides, so I wont repeat what they've said.
Main combo you should use in harashing is, dash in with then hit fast and after slowing, dash back with After getting SHEEN, remember to ALWAYS
AUTOATTACK between every skill. If 1 v 1, you should also wait between 1st part and 2nd part of the skill, but this doesnt work well when harassin in lane.

This goes so well with sheen, after every ability you get +50% att speed. So time your skills well when 1v1, you get 50% att speed + 100% att damage to autoattacks!

This is your primary skill. It has the lowest cooldown, and does the greatest damage. Also has the range, which u need in harassing. MAIN THING, is to put this on SMART CAST SPELL 1, it makes it so much easier to hit enemies with it. Also this proves to be very useful, when enemy thinks that they've gotten away to tower, just act like you don't care, and when they least expect it, jump in to the tower, throw your combo, and dash out with 300g. Also note that this does higher damage when opponent has least HP, so it makes it a good finishing move.

Cripple is your secondary skill in need, it gives you a bit damage, and most importantly slows enemies movement speed and att speed! It suites just well in your combo, so you can land a few autoattacks on your enemy, before dashing back to safety.

This is mainly your escape tool. If surprised, just dash to safety and your off the gank. ALSO can be used in offensive way, stay back and let enemy come closer, then dash forward with iron will and try to hit on him with your resonating strike or slow him with cripple. If he's in middle of minions, just dash on your minions, land cripple on him and autoattack until he will try to run to safety, then just get him with resonating strike, AND KILLING BLOW.

Last but not least, ulti. This ulti has many purposes, it can be used defensively if getting low on hp or just surprised, also can be used in team fights, to knock every1 airborne on its way or it can be used offensively, usually dashing behind the target and kicking him back. I usually get FLASH and EXHAUST for this reason, If im 100% sure the target is alone, I will flash behind him, exhaust him, and kick him to my minions / turret.

Well i didn't want to write a book, and the target group for this build was people who have before tried lee sin, and have maybe read guides already. The greatness in this guide in my opinion, is that this works great in 3v3 or 5v5, solo or teamwork. THE only con, I've recognized is that this doesn't work well on tanks in early game. But still, you should maybe try this build, if you like to be more of an "op" lee sin that kills in a blink of an eye. THE MAIN THING, is to play patiently, and especially in BEGINNING, later on you can hit back so hard, that no1 will try to solo you. Stay back, last hit minions, and try to land on your always when possible. 1 Thing, PUT AND ON SMART CAST SPELL 1 and 2 (in options, key bindings)