I think I am an ok lb player, sometimes I have good games, and sometimes I have bad games. But, I always feel like whenever I carry on her, I just screw over late-game and we end up losing.
I dont know if it's that I'm just bad or that she just falls off super hard late game. But, recently, I went 24 and 4, but still lost, and I don't know how it even happened.
Can someone plz give some tips on how to play lb late game?
you don't, you need to end it before late game
It seems my friend, that what you're actually looking for is some Siv HD tactics. Too Solid ones some people would say.
Go to your favorite Search browser and type: "Siv HD". That will give you a.. new perspective if i may be so bold to say so myself.
She does fall off in the late game. If you don't get fed in the early-mid game, you won't really be useful later on.
The only way to carry the late game as LeBlanc is to abuse your early game strength and finish the game before your enemy outscales you.
As said above, you need to end ASAP to be fully relevant.
Now in the very late game, you’re a threat (cause your q r w one shots the adc ) and should be playing as such.
Get 
and play with vision as much as possible, try to focus the target you need eliminated. If the target doesn’t know where you are, it will freak out and won’t play the teamfight properly.
Abuse your catching potential, play with vision and be the omnipresent threat :)
LeBlanc does not carry late game.
End the game before 30 minutes.
If you're not fed, you're useless. WELCOME TO ASSASSINS IN LEAGUE.
That being said, if you can get ahead mid or, especially, early game, you can just go around nuking people in .5s from 100-0. My advice? Target nearest squishy and murder the fuck out of them. You'll either force a back, or just get a kill.
How do you carry as Jinx on early game ?
You don't, same for LB on lategame.
