Ap help

Can ap get some help with last hitting/cs. Its so hard for for ap characters to last hit with basic attacks because there is no scaling with what they need to build unlike like with ad characters. So if you use your abilities then you're low on mana and can't fight. Maybe the way ap scales when you hit turrets the same way with minons. But late game might be too much so maybe scale to a cap or something. just some thoughts thank you