Something that helps me...the surf is a great classifier of targets due to the wave action, winds, and current.......then the shape, size and weight of the targets, so many factors that classify targets for you.
Rarely do I dig bottle caps, pulls or light trash and this is wetsand to waters edge. Every beach is different so what works for me may not work there but If I am finding light trash, I know there is another lane of heavier targets in there somewhere. Several years ago I seen this pattern after hurricane Bill (2008), then Sandy in 2012..Ocean City Maryland....where the largest waves were breaking on shore...... was a line of gold rings..and clad coins. In closer was all the trashy light targets.
A few years ago as I was walking out (In the water) on one of my favorite beach's (in the Chesapeake Bay) I noticed there were targets every where, I dug a few and they were trash..In this I noticed it is rare for trash in this area..or any kind of targets. I get out to the next low area...Silver coins and Gold..think I got 3 gold that day. So there are patterns...2 different beach's.