Is there a reason that I should just start at the highest power and frequency and then just back up from there? I'm using a Bitmain power supply from my old L3 so that should have plenty of power.
The miners will peak at a certain power level and frequency combination. You usually want to achieve your target hash at the lowest power consumption possible. It's good to use a power meter as well. If you start at the high end you will be consuming more power than necessary for a given hash rate.