Consistency in signal is number one!
A good two way hit that is consistent is ideal.
A silver type one way ( 45-48 ) hit will still produce good finds, but will more than likely be a rusty, bet nail, fencing staple, or barbwire. You'll have to dig a few (per location) to determine if that is what they are. There are other signs to tell you if your on a iron or not in those situations. They include:
1. A higher Fe number (usually above 17)
2. Switch to quick mask and listen to the length of tone. Often you'll be able hear how the nail is orientated.
3. Nails will often be "down and out" of your plug. As you dig your plug and start chasing the signal, a nail will often be down deeper and you'll find you're going out from center of plug 4-5". Can be a coin on edge though.
4. Again, you'll never know for sure unless you dig it.
I use TTF in areas where I'm going to dig "ALL" non-ferrous siganls. ie. Fields where towns were 80-120 years ago and old house sites. and places where schools were 80-120 years ago.
Here in central Nebraska, the towns were not platted in my county until about 1883, so that is why I "dig all" at these sites. I'm looking for "Settler Era" coins and relics.
I did a video on "Falsing", that might be helpful. As far a silver sound, in Conductive tones, the falsing will resemble silver chirps and need to be identified as such. The only way to really understand these are to hunt and listen for that consistent hit. Falsing was my number one nemesis, when I was new to detecting.
Use a good handheld pinpointer.
Also, coins on edge will often be 2-3" to the side of your pinpoint, so be aware of that.
Build a coin garden to test your swing speed for different depths on coins. At least plant a nickel, Indian Head, Wheat, and silver dime and test your machine and swing speed to optimize yourself.
Personally I use Auto +3 and would start there and keep it there. Too high a Sens. can be frustrating when learning the machine.
The best advice is to just hunt and dig. It will start to stick after many hours. Don't get discouraged.
Ask questions, there is very good advice here on this forum.
NebTrac