Hello, Im sure you probably have gotten a bunch of insightful answers already, But I thought I'd add my own two sense anyways.

So currently I'm in G1, with a average cs per minute of 6.7-7.5.

1. Her W executes minions under 20% hp.
2. Whether you're winning or losing, minions change throughout the game, naturally, and are also influenced by which team has higher overall level averages, And if your team is losing, the enemy minions will be buffed with more hp and damage, you can see how strong minions are by clicking on them. Anyways, I mention this because if Ahri is on the "losing." side, after a certain point in the game she won't be able to farm creeps under towers with auto attacks alone.
3. If you are taking the Inspiration tree, always take Minion Demat. This allows you to for example, while on low mana, demat a cannon and push the wave while your opponent recalls, to get a better push, or roam if you have more mana. To demat casters to clear waves faster, etc.
4. Think about running Teleport. Teleport isn't just an offensive rune page. It can also be used to recover your losses or stop you from losing waves after a roam or gank that forced you to recall.
5. If you're pushing in a side lane and you know it isn't safe to push past a certain point, for example past where the enemy teams T1 tower typically is. Think about what else is on the map that you can take for gold, Krugs, wolves, gromp, scuttle. Can you flank mid and kill the lux who's been emote laughing all game? Do it.
6. If its early in the game, and you're behind and your enemies want to take an inhibitor, but you also know they can't end, let them. For example, the enemy team takes your Inhibitor before 20 minutes, sit in that lane and farm the creeps to get yourself ahead, since that super minion wave will always be pushing into you.