Check every target with AM/pinpoint. Sweep slow/fast near/far. Sweep at multiple angles and speeds to help define shape. Sweep high/ low to determine depth/mass.
Start calling your targets out loud, then dig and compare. Using this method has built up my accuracy and confidence immensely.
Bury some tabs and nickels in your test garden at different depths. Slowing down now will speed you up later.
The stock 9X8 is an excellent coil to learn on. The 5.75C is a completely different experience for me. I'm digging pop cans again when I use it. It actually hit on an unsmashed pop can from 2' away and parallel to the coil. Crazy sensitive to aluminum. You might notice how AM sounds a little more exited when sweeping aluminum.
Quite a bit of info packed into that AM hum.