Headphones, Speakers, and Better Ways
If you use headphones to operate your detector, apply a piece of plastic tape over the speaker grill on the box, to keep dirt out. It is amazing how much sand and other fine particulates will find its way into the speaker area, over time, and that is not a good thing. A deposit of dirt in the speaker collects moisture, stands a chance of getting into the box proper, and will ruin the interior speaker fast.
If you get in a bind and have to use the metal detectors speaker, the tape can be easily removed, or even left on, because on many detectors you can still hear a signal fine if the speaker grill is taped over with light plastic packing tape. This is actually an improvement in design that, to my knowledge, no one in the industry has employed yet.
Super Sensitive Metal Detecting
The All Metal mode on a good detector is usually so sensitive most people do not use it. Most All-Metal detectors can detect a coffee can from many feet away. Many detectors in All Metal mode will detect shoelace eyelets and zippers. That means yours. While you are using it. Takes some getting used to. But worth it.
When hunting a well known and supposedly worked out area, where all the trash has been dug as well as the shallow targets, its relatively easy to go into a no-discriminate All-Metal mode and get some deeper things, and lots of times the deeper things are nicest things.
Metal Detecting Historical Gathering Places
Some of the best places to metal detect are abandoned fairgrounds, and many times the earliest fairgrounds are now inner city parks. These can generally be hunted without a hassle, though the layers which represent the early times are often way too deep.
When some work was done on certain parks in NYC, the layer corresponding to the earliest time periods was sometimes more than four feet deep! Once exposed this layer was a bonanza for a few lucky people with metal detectors, but you must understand that this is not an isolated event, and more early coinage gets uncovered and reburied every day that has yet been found.