Find a vintage motel or hotel postcard on eBay. Pick something from your local area so you will know the streets, more or less. Use Google Street View (find the location on the back view of the postcard) see if you can find the motel now. Is it still there at all? If so, is the name the same? Spot the differences between then and now.
Take it on the road and visit the site. Get a photograph and (if you have a site) post the then and now images. Find some history, if you can. Or design a history for the motel yourself. Who owned and operated it over the years? Did they love it, grow too tired to keep it going, run out of money? What changes happened around them in the local area?
I found the Caribou Motel in the present, it’s gone. Replaced by a new gas bar. Nothing left of the old motel and diner except the space around the new building. You can see some curb out by the road and the parking lot is bigger than the current commercial business would need. Small hints at what once was.
You can see what became of the Caribou in urban exploration photos from CopySix and other explorers who posted to Flickr and Ontario Abandoned Places. Note: the CopySix post has a comment from the original owner’s family.