Write down as much of the plot description as you can. List major and minor themes, character names and plot lines. Uncover as many production credits as you can remember, as it might be helpful later to verify what you have found.
Let's use the example of Hallmark's "The House Without a Christmas Tree." Made for television in 1972, it is a beloved if now obscure movie. Using google.com or another search engine, place your description into the search bar. Try descriptive phrases including phrases such as Hallmark Christmas movie, house without Christmas tree, or Addie does not have a Christmas tree.
Further investigate by searching the Internet Movie Database at imdb.com. Place a short description of your movie into the site's advanced search feature by "subject." Comb through the listings of film titles. Often, you will find your particular movie title through the process of elimination.
Study and click on the links that result from your searches. Enter what could be the title into another browser search, to see what links surface. Once you have what you believe is the title, use it in a search on Amazon.com or Netflix.com, where the film might be available for sale or rental.