as i covered in masteries how to use her skills in lane you also need to know the times to leave lane and help mid as leblanc can do this without adc's help but can also leave adc at a disadvantage so the best way to do it by getting your Q W dmg off and then tell adc to play safe this is a risky play but can pay off for mid lane. as the support leblanc the best way for you to zone enemys is to spam Q W to put them low the reson for buying fairy charm is to let you get the mana you need to poke enemy

Pros
-Good Early Damage
-Can prevent ganks quite easily
-Good for blocking skill shots like Caitlyns ult as leblanc can use w
and most people with skil shots by just using w into them
-Can Jukes Most Champions
-She can make people waste abiltys with passive -can out dmg most supports

Cons
-Countered hard by stuns like taric leonas stuns are hard for her to hit because of W
-quite squisy early game
-adc's with lock on abiltys like quinn
-adc need's to attack at same time

For Fast Damage if you want kill Q a minion then let it refresh cooldown then R Q W then if not dead E to secure kill for adc Q E R then you get a double root so the adc can catch up and get an easy kill so main combo have Q ult then Q again then W

Siv HD+ocelote plays support leblanc very often and is good at doing it but with this build you can be the best help to your team Play Video as this is kinda troll game but then i tryed with this build and i found it worked quite well and im looking forward to the next season making supports get more gold making this work even more

if your lanes losing as leblanc just go mid and help get a kill because this will put your mid laner ahead and this may give them the idea to come help you at bot lane if this does not work you can always just go full ap and kill the adc yourself but only do this in extreme conditions

Having a adc with hard cc or slows can make your E very good by giving time for cool downs on adc and yourself making it all the easier for you to get the kill on the target like Vayne,Varus and Jinx would be a good few

Taric
Draven
Annie

if you're playing ranked and you want to win bot lane these are the bans you probaly want to go with because of high damage early from draven and stuns from mid and support can get you killed

hope you like my firsts build/guide for leblanc if you have any things that you think should be changed leave a comment thanks for reading and Goodbye