Ok all, here is how I search out films:
First, google your keywords (make the words/phrases short, and use the most unique ones...it helps to stay away from gender pronouns and years) with site:imdb.com at the end of them, just like hadaway says. If the first few pages prove useless, go to the next step.
Second: Use the advanced title search in IMDB. Give/take 3-5 years for your search years, from when people say they saw it, or it came out. If they saw it, give 5 years on the max year, and either leave the least year blank, or the first year of the decade you think it could be. Just use whole years (like 1984), not full dates (like January 14, 2010). If they think it is a movie, select film, video, tv movie. You can use the others lke mini-series, documentary, short, tv episode, etc. after deselecting those, to make your next search shorter and not repetitive. I would not ever select tv series, unless that is what they are looking for. Genres are tricky, so only use one at a time, and only to what you think the movie could be, or what they suspect it is; if it is a sci-fi comedy, look under sci-fi, because it may not also be tagged with comedy. I would stay away from keywords for now, until you become very familiar with the system, so you know what people may write in there, but leave out of plot. Fill in the plot words with only one word, preferably a unique one. If the word has a synonym, search those too, after, one at a time. If they know it is of a specific language, you can select it (only one though). After that, I change the detailed number to 100 and sort it by year instead of movie meter; it is ordered better for me. Leave the rest of the fields unselected/blank, and click search. Look through and see what looks like your movie.
Third: Google unique phrases, words, etc. using combinations of quote operands for specific phrases that are supposed to be written like that, only, and - signs for things you do not want to show up, if it is in the pages at all. Do not use spaces. Read up on google operands to help you further. Add Yahoo Answers in there for a place where it may have been asked before, or referenced. If there is a specific plot style like virtual reality, for example, google virtual reality movies, and then see of there is a result from allmovies.com .... they categorize movies by obscure plot points, a lot.
Fourth: Reach out to the other movie help/movie naming sites, to help your chances of finding it. Just google them.
Five: Reach out (contact through contact us link, comments in their blogs, etc.) to experts of the genre/subset, by looking up things like horror experts, slasher experts, romantic movie experts, etc., facebook pages, or websites that are based upon these things. Contacting authors that wrote the book on certain areas is of help too (ie: book on jiangshi, or silent film comedies), since they definitely know the subject. They can at least lead you in an area, if nothing else.
Six: If you say the movie you are looking for is like another film, whose name you can remember, google movies like _____ .
Seven: The user Silencioso taught me how to look up something if you have a picture of the actor (it can be used with all pictures, with varying results, I presume). You have to use google chrome: locate the picture on the web, right click, and then search by image. This will look for that picture from other sources, and could provide you a name.
Eight: If you saw it on netflix instant, go to your pc, look under profiles, then history. If it was one of the last 100 titles (I think) you watched, it should be listed there. If it was a dvd you rented, it should have your full rental history. I cannot be sure, but other services may have similar history profiles.
Nine: If you know a character name, especially the obscure, try to spell them in different ways to see what you come up with. Also, utilize the google live search, that shows other's searches that started with the letters/words on the screen; you may recognize the word you are looking for in it, in a way you may not have spelled it.
*If looking for horror, there is a facebook group called vhs horror collectors unite, that can be of help. I know several others including experts with blogs, etc., for horror. Just comment here if you want them.
That is all I can think of right now, but if anyone needs any help, just comment, or make a thread directed at me, if it is ok with NTM. God speed.
Edit: Some of these techniques came from me, and others I have learned (unique words, site:) from hadaway and others. I do not claim to invent these search types, and apologize that I did not mention that the unique keywords was written in hadaway's blog. This is just to show how I search, which can help people. Thanks.