Hi bilk
The MXT is a powerful detector and it hits hard on the first 6", so a lot of targets under the coil in that range will make it go nuts, what I do when I get a new detector is find a clean area and lay a group of targets on top of the ground, spaced about one foot apart from each other and practice on them, I like to see how the machine reacts to each target at different settings, it is a good idea to only adjust one setting at a time, seeing how the detector works on targets on top of the ground will help you understand what is going on in the ground. Swing the coil over the targets at different distances away from each target, notice the change in screen readings as you close in on each target.
I use Uniprobe headphones and a cheap long flat head screw driver from the 99 cent store and grind the sharp edges smooth , so not to damage old coins when I hunt, I always start in preset mode, relic for me, trigger forward, disc on 0 and adjust my settings from there, sometimes I will crank disc up and cherry pick silver and work my way to gold by lowering disc as I go, it means making multiple passes over an area, but the more time you spend using your detector, the more you will understand what it is telling you. The most important tip on metal detecting is to make a small a hole as possible and fill your holes before moving on to the next target, believe me digging up other peoples property will cause a lot of drama and sometimes involve your local Police Officers.