Try to keep the battery range between 20 and 80% most days.
It is OK to go higher or lower if necessary but avoid it if you can.
Charge more than 80% if you really need it but don't let the battery sit at a high state of charge 90+ for hours or days.
Most of the time you will charge at home and most people drive 60 miles a day or less so charge level of 80% is not an issue.
If you're on a road trip charge to what you need to get to the next SuperCharger or your destination.
Charge rate slows down as the battery gets full so it is a waste of time to charge more than 80% at a Super Charger unless absolutely necessary.