Pros:
-High mobility

-Pure dmg

-CC

-Strong laningphase

Cons:

-Easy Pick

-Charm important to hit

-No mobility without Ult

At the laning phase you should always try to Haras the enemy with our
strong Q and Burst potentional at lvl 6.

If you have to back before 6 bring an extra ward because your pretty easy to gank without your Ult.
Try to roam since lvl 6 because of Ahri's High mobility and CC

Try to complete your Core Items to get a lot of burst potential .
After hitting a Charm it's easy to hit your Q on your target.

Important for Ahri is to dont get out of Position because u will have to waste
your ult or flash, since then you will have no mobility.

After Completing Dfg , look for picks in the Jungel or other Lanes you will noticed
even if your behind you will do alot of Dmg in a 1vs1.

Focus on he Carrys of the other team to get alot of burst on 1 target.

With Zhonyas you will be abel to Survive a teamfight even if you go all in.

Before teamfight try to charm a squishy target and burst him down even if you
dont kill him they often have to back and you will fight 5vs4

Look for picks and try to dont get out of Position you can be easily deleted
when you get CCed.

Just try to play like Mid game but never go alone in an unwarded area.

Bring a sweaper with you and a Vision ward to get good picks on the enemy carry's

Stay in team and try to get a pick with your Charm even you will hit a tank your
taem still can Burst them down or low enough for a back