Best Spots To Metal Detect?

Patience is key. I suggest researching your town / city to find the original areas and buildings.

If your looking for those quick & easy targets with very little digging that seem to replenish themselves every week try school playgrounds. Any playground that has bark chips or sand. There's 11 elementary schools & two parks in my town. I hit them every 2 or 3 weeks and can pull $15.00 to $30.00 on a good day not to mention about 30 or so Gold rings,Gold charms bracelets and quite a few silver items to boot.
I find the best time to go is on Sunday mornings around 8 or so. Not a soul around & very peaceful & quite.
Here's a picture of some of the silver items I've found over the last few months.

Over 30 gold rings is over a period of 3 years or so. I'm not metal detecting to return items to people unless it was a class ring or something along those lines. If you want to try to return item's you find that's great but I keep 100% of the items I have found. I have no problem with that

I'm not really into detecting jewelry (I don't have the patience to dig pull tabs all day), but I've dug several hundred silver coins including about 20 halves and a couple silver dollars. Many other old coins too from the early to late 1800's. 90% of these were found in city or county parks, supposedly 'cleaned out.'

These finds were made after I changed detectors, and the previous one I had spent $1,000 on.
I spent another $500 on a used higher-end brand.
My finds were made after I changed manufacturer, and sorry I won't mention the brand.

The treasure is there to find. Depth has nothing to do with it, as I've dug civil-war era coins at 3", and newer clad at 10". Experience and technique is what counts. Ya gotta put in the time.
Hone your skills. I've used a coin garden in my yard, items buried at certain depths. I learned most of my machine's capabilities in a short time using the 'garden'.

I'd also like to mention that private yards are great too, they're kind of the final frontier. I got good at door-knocking several years ago, and received a permission 4 out of 5 times. Old city yards seem to be the best. Curb strips also, but I make sure I get permission from the homeowner, even though the city owns the strip between the street and sidewalk, the homeowner usually considers this strip their property, they mow and maintain it.

Talk to some old timera too to find out where old buildings or houses stood. I see a lot of guys detecting out in the middle of fields early and late in the planting season that find old coins/relics. Either old house or schools had stood where they are detecting. I don't have the patience for that though and prefer a nice old farmhouse etc.

Go down to aNY McDonalds in the morning and and to sit with the retired guys and pick their brains oof hot spots when they were kids. Also you can find stuff in a heavily search area. I had a buddy in Washington state that pulled a gold nugget from a park that was search every week by someone.