A good place to look is in old flower beds or small gardens. Rings and bracelets could have fallen off when working in the dirt. Children could also lose small toys while playing in the loose dirt next to their parents. A flower garden seen from the kitchen window would have been a good place for the lady of the house to bury a cache of money. The man of the house would have buried a cache of money someplace that could be seen from the bedroom window. Loose change could have been dropped when getting in or out of vehicles. Change could also have been dropped on the side walk or path to the house. Any place the family could have relaxed outside, especially around large trees used for shade, would be a good place to have money drop out of pockets. Look for depressions showing where large trees might have been. The place where a clothes line might have been and outside under the kitchen window are two places the lady of the house might have laid something down or dropped something.

Inside the house a likely place for a loose board hiding hole would be in the kitchen, or the master bedroom. A loose stone in the fireplace is another possibility.

Check the paths to and from the parking area and the rest rooms. Also look around the Benches or any place someone would sit (under a large tree). Where the parents would sit to watch the children playing on the swings would be another good spot.
In older parks check in front of bandstands or areas where people would sit, to listen to bands playing in the summer.
Another good place is baseball diamonds. Check the infield and the area where the players would wait to play. Also look in the area that the families and fans would watch the game from.
One place you can generally find coins is in the playground. Under the swings is one of the most productive areas while the other amusements also provide good places to check.
If there have been fairs in the park look where concession stands might have been.

Any place that someone would spread a towel would be a spot to loose something in the sand. Rings and bracelets would work loose when playing in the water. Change could fall out of a pocket when getting in or out of a car. Where ever a concession stand might have been is a good area to search.

Go to your local " do it yourself " coin operated car wash -  Look for the place where they dump the contents of the 25 cent vacuum cleaners. Search the piles and see what a gold mine they are for coins and rings.

Search old farm mail boxes and pasture entrances, lots of coins are lost there.

Sidewalks - also look for sidewalks that are being torn out for construction.

Flower beds at older schools.

Try looking at old road side stops - Especially the ones with a bunch of picnic tables.

Your backyard  - Be careful not to dig any underground power lines.

Hill sides - Coins from children rolling down them, they can lose all the coins in their pockets when they do.

Flea Markets

Middle Schools - middle school students usually pay cash for each lunch they eat, get change, and go to recess right after the lunch, look where the kids go in the school yard for recess, that is where the coins will be.

Vending machines on concrete slabs - perfect place for a coin to hit the slab and roll onto the grass, also look for pay phones and parking meters these are A-1 places to look and they only require a minute or 2 to search.

Stores, or places where people have money out - the PERFECT place to look.

Playgrounds - they may be oversearched, but you are likely to find something, there has to be a few of them that haven't been searched.

Fair grounds - lots of people in one area, people can easily drop coins where rides are set up and where there are concession stands.

Beaches - Hands shrink when they get wet from swimming, then they play in the sand and their rings fall off.

Wishing Wells - people may drop a coin on the outside of it while trying to get one out to put in it.

The local library - you aren't going to find coins there, but it will tell you where to look, research.

The Internet - There is a wealth of information regarding places to hunt if you take the time to explore online resources.