Basically, her rework changed her from the "press 3 buttons and kill you" to the "press a button, wait 1.5 seconds, THEN kill you".
Her basic combo for lane phase areeeee:
lvl 2: W onto laner and minion wave>Q laner. this pokes laner, procs thunderlords, and shoves wave.
lvl 3: This is where things get interesting.
E>Q>W
W>E>Q
Q>E>W
The combos are endless. Landing your chain is the only change to lvl 2 combos.
lvl 6: AHA! Here is where it gets fun!
Is your lane getting a gank from your jungler?
W>E>Q>R+E. THis roots them for a good 2 seconds straight and allows for any jungler to deal their damage and cc.
Damage combo?
E>W>Q>R+Q. This is just a basic combo. For damage.
There is no correct LeBlanc combo per say. If you need CC, use your double chain (first lvl 6 combo listed). If you need more mobility, use your double Jump!
Make sure to wait to use your second damaging spell until after your passive is ready to be proc'd.
Always keep track of your W return location. A good LeBlanc player will use their W back to possible net them a cheeky kill, or catch their opponent off guard OR dodge skillshots effectively.
I can go into further detail if you need me to, just some basic stuff :D
LeBlanc is nowhere near as easy as people make it seem. Yes, I enjoy one shotting adc's, but I gotta get myself fed first!
~Talavin, the Deceiver