Brainstorm all the details about plot, genre, setting and actors that you can. You will pull your search terms out of these details. Even hazy memories can help you to pinpoint whether the film was a Western or a Science Fiction title, for example, which will increase your odds of finding it considerably. Write everything down.
Write down alternatives to your search terms. For example, if the main character was a “trapper,” you can also use “mountain man,” “explorer,” or “hunter” as alternatives. The database might contain one of these but not the others, so alternatives are the key to an effective search.
Search one of the following databases, listed in order of effectiveness:
http://www.imdb.com/Search/plots
www.wikipedia.com
http://www.allwatchers.com/
Enter general search terms combined with one specific detail. Let’s imagine you are searching for the film, "Jeremiah Johnson," and you remember the plot about a trapper in the West who is forced to fight Native Americans. Start with search terms like “Western” and “Indians” and add something more specific, like “mountain man.” "Jeremiah Johnson" comes up early in the search results using “mountain man Indians” (See Source 1). Staying too general will give you a huge list of Westerns to sift through, and getting too specific risks missing the title because that detail isn’t in the review or summary itself, even though it is in the movie.
Play with different combinations of your search terms with some persistence. For example, entering “mountain man revenge” into the Internet Movie Database does not find "Jeremiah Johnson," even though all those elements are in the plot. One different word, “Indians” rather than “revenge,” makes for success in our example. The results will change, sometimes narrowing and sometimes expanding the results.
Read through the results, listing new search terms that near-misses suggest. The search results likely will list films with some similarities to your lost film, and these can jog your memory. Add those to your list of “must try” search terms. Hopefully, before you reach this step, you will have found your film title.