Hey there! This is the Build I use for LeBlanc in normal games! You can also follow this build in ranked games much better with a Banshee's Veil instead of a Rylai's Scepter. You can get decide as the game flows tho.

Now about masteries. For sure you get Arhaic Knowledge from offense and Awareness / Blink of an Eye from Utility.

Now about Runes! Thats the thing! You go Marks Magic Pen / Ability power per level Glyphs/Seals and Flat Ability power Quintessences. The reason I'm doing so is that at level 4 you can easily get a kill against any champion.. It's Flat 15 Ability Power + 45 Ability power at Level 18.

Flash : You can avoid death like a million times by using flash and then "W" or even Flash , "W" and then "R". I always have less than 4 deaths and im a totally aggressive player.

Now Ignite: will help a lot on laning against Vlad or any other character who can heal up in any way.. Also is rly useful for your first kill on level 4. Is the extra damage you need to take down the enemy champion.

So for skills, leblanc usually starts fight with "Q" so its really useful to have it at max rank possible / after "Q" go on with "R" then "W" => target less than 10%.

So get first "Q" then "W" you need it to harass and avoid any unexpectable ganks.

So what about farming?? LeBlanc is a difficult character to farm..but if you find the opportunity(ex. 10-20 minions gathered) don't hesitate to use your "W" and then "R" to farm them..

Just take a fast look at it, try it.. I'll get you some more info and better ways of playing Leblanc in a few days.. (kinda busy now) I'll edit this build soon. Thank you! Have fun while playing!