If you want to upload a shot, just follow the uploading process. In the second step (Choose) just typ a totally nonsense title like jdshhdfs (only if you're sure the movie is not yet in the database).
Then you will see the following text: "# We did not find anything # Maybe try to simplify your search # You may also provide an IMDB link or and IMDB id My movie is not listed. Create a new one."
Then you just click the button and create your movie.
If you want to add a movie without adding a snapshot, just follow the same steps, but stop the uploading after you added the movie.
And make sure the 1st title you enter is the *original* title of the movie: the one that appears in grey, below the main title, on its IMDb page (unless you're registered and have changed this setting).