-The m.pen. marks are for obvious reasons.

-I use greater seal of clarity because some champions you'll face in mid need to be poked a little more than others and these runes will give you the mana regen needed to finish them off.

-The CD glyphs combined with your CD masteries should give you just enough CD to cast off another Q to finish them off after expelling your full QRWE combo.

-I highly recommend flat hp quintessences because LB is squishy and these runes + the masteries will allow you to survive long enough to burst down your opponent.

In this guide I will teach you my play style on LeBlanc and give a few tips & strategies along the way.

Your Mentality as LB
As LB, your mentality should be that your main source of gold are champion kills.
Last hit minions when you can, but your priority is to take down your opponent.

Early Game
TAKE MID NO MATTER WHAT
Your goal is to disable them as early as possible.

***The strategy is to kill them right when you hit level 2. If you can't, then do it at 4.***

Poking Combo: Pace back and forth BEHIND your creeps --> run in --> Auto Attack + Q + Auto attack --> run back. Repeat.
Try and hit level 2 before he does by killing a creep or two more than he has.
Right when you hit level 2: Flash --> Q + W + Ignite + Auto Attack --> DONE.
If for some reason this fails (they flash away, use heal, etc.) simply retreat and pop a health pot and continue farming (last hitting only, don't push).
If they pop a health pot too, try not to use your Q so you can regain some mana for the next opportunity (which is at level 4), instead, just poke them with your Auto Attack to cancel out their healing.

**Your goal now is you MUST kill them at level 4.**
Since your Flash and Ignite combo are out of the equation at this point, make sure you have enough mana to perform the next combo: Q + W + Auto Attack + E + Auto Attack + Q.
You can throw in that Auto Attack in between W and E because they will probably try and run to gain some distance, giving you a more accurate shot with your Ethereal Chain. Your Q will be off cool down by the time the chain snares them.

If you were able to kill them at level 2, go to town and purchase an Amplifying Tomb, 4 Health Pots, and 1 Mana Pot before you return to your lane.

Level 6: Once you hit level 6, you can pretty much kill your opponent every time he comes back to lane =). Simply poke with Q once or twice, then burst at him with your Flash --> Q + R + W + Ignite combo. (Chain if necessary).
Go back and purchase Mejai's and Sorc Boots.

Mid Game
When you have Mejai's and your Sorc Boots your path to disabling the other team begins.
For me, mid game begins either when I hit level 6 or have both these items (whichever comes first).

At this point you can take 2 paths. You can either continue farming up the enemy champ in mid (who has probably switched lanes by now cz his team raged at him) OR have an AD carry take over mid for you (which is the path I usually take).
The reason I do this is so he can level up faster and you can go around getting stacks for your Mejai's and "disabling" every lane by sending them back to town and denying them of valuable exp. He doesn't have to worry about being underleveled because if you did your job of disabling mid, they will both be at the same level.

Your next goal is to save up for Rabadon's Deathcap. If you have been getting stacks, by the time you get Rabadon's Deathcap (which is usually around the 23:00 min. mark), your AP will burst to about 400-450.

Late Game
Congratulations on disabling the other team. Everything is downhill from here.
The core build is complete (Sorc Boots + Mejai's + Rabadon's) and the rest of the items are really up to you.

Suggestions:
Get a Banshee's Veil to preserve your precious stacks.
Get a Void Staff since late gamers usually build a resistance to your ridiculous AP.
Your mana regen is around 30 so all you would need is some spell vamp to stay in action, so get Will of the Ancients.

A lot of LB builds I've seen and experimented with seem to really rely on Mana (ie. Archangel's Staff, Rod of Ages, etc.). LeBlanc doesn't need mana lol. But then again.. it's up to you so w/e... I never needed it. You just need to learn not to spam like a nub. You can determine whether or not you can burst them down to zero health with your combo.

Riot was really out of their minds adding this champ to the game because she can confidently take down every champ sent to mid. Mid is LB's territory.

Buy wards... because the only thing that can kill you is stupidity and ganks.

Decide at the loading screen whether or not you feel the opponent's team composition will take you into late game (40+ mins). If you feel it will, build Rod of Ages ASAP. This will give you the needed HP to survive most harassment. Remember your role as a nuker/assassin and so you only need enough defense/health to survive certain situations, other than that, you have 3 flashes... c'mon that's gotta be illegal...lol

Champs that will give you a hard time to get that level 2/4 kill:
Anivia, Pantheon, Nidalee (if she gets Primal Surge first)... that's pretty much it.
Well, they're actually beatable if you out play them correctly.

Next, I will give some strategies on how to take down some champs that are a little bit difficult to deal with

Ashe: Since she's always staying back and waiting for the right moment to use Volley... outplay her! Run in towards her for an autoattack, but DON'T. Juke her by going back or behind a minion on your side. She'll think you're coming in for an attack so she'll waste her Volley. Keep in mind it has a 20 sec. cooldown. She can't do anything for that time period so get behind HER minions and zone her.

Caitlyn: Similar strategy as Ashe. Try to avoid running in the center near your minions because she will try and shoot you with Piltover Peacemaker. Juke her the same way by running in, but this time, instead of running back or behind your minions, run to the side. Try to count her shots. Her passive makes her shoot for 150% more dmg every 8th attack. Make sure she wastes in on a minion. Don't go in for the poking if she's got it stacked.

Ezreal: Learn and anticipate his rhythm. He will try and Mystic Shot you if you're in his line of sight. Always try to keep a minion in between you 2. Watch yours and his minion kills, and make sure he doesn't level up before you. KILL him at level 2 lol.

Karthus: ...just sh!t on him... I don't even know why I put him here. But if you're really having trouble (lol), leave a comment and I'll really add some notes.

Katarina: This tough cookie can be outplayed easily. Q her and she will most likely burst towards you with Shunpo... use W when she does lol. E her when she retreats, then stab her with another Q. The next time she uses Shunpo, she'll die.

LeBlanc: Get W first instead of Q. Run near the "sides" of the minions, maneuvering her to run on the opposite side as well, or at least away from the minions. Cast W on her when you're positive you won't hit any of her minions with it, because if you hit them, they will turn their attention to you. Your combo for this will be: Auto Attack + W + 2 Auto Attacks + W + Auto Attack. Think of each Auto Attack doing 50 dmg... That's 200 dmg plus the dmg of your W. This combo will out damage her stupid little Q and also provide you with escapability at level 1. As a matter of fact, this is what I used to start off with when I notice that the other guy didn't buy any potions.

Vlad: sh1t on him with the same technique as LB.
Things to remember - His Transfusion has an 8 sec. cooldown, so zone him out for that long and make sure he doesn't use it on you. After seeing the damage you did to him with your W, he will probably pop a Health Pot, so poke him with your Auto Attacks to cancel it out.

When your team is winning and is practically at the gates of their base, there's a little something i like to do called "fishing" >=).

Get wards and place it along the inside of their wall so you can see them running up and down to each turret trying to defend. When you see a squishy get within range, Distortion onto him (from the outside) and burst him down with Q + R. Help your team out by even depleting some of the enemy's HP so they can rush in to kill them and even possibly take down the tower and inhibitor while they're at it.