The Netflix show Stranger Things was pretty inspirational, so I went and created this fictitious small town called Milton New Mexico as a setting for a similar style game. To create the town I used a modified version of the Microscope collaborative setting rules, and all the players were able to contribute ideas to the town's history and various mysteries. I then designed a map to tie everything together and give a common sense of geography. (For the actual game the players all rolled up 9th graders in 1986. I used the Bubblegumshoe RPG rules set.)
The campaign is on haitus but the players have enjoyed putting the clues together about the "strange doings down by the Circle K", and are keen to come back to it in a few months.