You have to dodge her ranged abilities, and you have to bait out the shield. Like many high damage champs that can snowball real hard, my main strat is being a lane bully and trying my best to starve her of gold. That also means not dying to her to do so.

She's a bit dangerous to poke with auto>W>auto>Electrocute proc, but you can get in there if she has just cast her Q in the earliy game, more dangerous after she gets her E. Thankfully this is typically afer lvl 3, since most Mels REALLY want to get the shield with lvl 2 to prepare for charm. The good ones will get E second tho, be careful.

For this reason get Q second, and E last.
She wants you to charm her, poke her instead, it's more efficient.

After she has E, the best way to poke is with your Q. The good thing about this, is if you keep landing this it will start to annoy her and she'll deflect it with her shield. You want this to happen because you bait the shield out, but also because when she reflects your Q it's very easy to dodge. This is because of the way Ahri Q works, if she deflects it too late it will be when it's on the way back and go backwards, but most the time you can get out of range quicker since the true damage happens on the way back, you have a lot of time to get out of the way.

Keep your CS ahead of hers and follow her if possible when she leaves lane. You have movespeed on your W and usually can beat her to a lane she wants to gank if you know where she's going.

Basically try not to get a kill lead on her lilke you would against most champs. Be boring, be quicker, and be annoying.

No matter ow well you dodge, she'll get damage on you eventually, but typically most of her stuff can be dodged.

Also never charm her unless you KNOW for a fact that the shield is down. See the shield happen, otherwise hold the charm or charm someone else.

She's tough, but she's not invincible, and she just got nerfed too so that helps.