I've watched fellows pinpoint on a sandy surface and use the X method until they are sure they have found the strongest signal in both directions then ... mark the sand with the coil imprint. Of course this wont work for solid soil. I've been putting a golf T down where I think the strongest signal is then recheck and move it if needed. Sometimes a little pebble works and I kick it into place as I recheck the area. I'm a novice, and it shows! Seasoned MDers get pretty good at spotting the location where the best signal was found without using a physical marker.
The target spot is just forward of the shaft pivot connection.
Also another marking method is to get the strongest signal spot then push the coil forward until the signal stops. Place your toe at the rear of the coil and that is where you should dig.
My first inclination before I dig is to use a hand held ProPointer just in case the target is so close to the surface that I can scratch it up with a flick or two of a knife. ProPointer does not have much more than an inch of detection range. A good many of the coins I've picked up are recent drops anyway.
Two days ago I watched a fellow use a small shovel with a long handle to shove into the ground, push forward on the handle to make a temporary slot in the ground. Then he would use his ProPointer in the slot to get the exact location of the metal "find". Really easy to simply stomp the slot closed leaving a nearly invisible soil disturbance.
M