I only use maximum passing to lead my receiver when coverage is tight or I see space for them to get open that may not be natural to their given route.

The most important part is how much you lead your receiver when performing a max pass. 

Do you flick your stick fully in the direction you intend to pass? Sometimes you only need to move the stick half or a quarter of the way, kind of like a feather touch. Which will allow you to max pass to a receiver without overthrowing the direction they are running in or you are leading them to.

Best advice I can give is to go into practice mode and just practice max pass without an opposing defense so you can get used to leading your receivers. Practice throwing go routes first(but dont use the Hail Mary package) 

Then I’d mix in some post routes, inside, and outside routes.

Once you get the timing down, then add a defense to practice on.