Depending on the program, there should be an option to save to a .iso file, dvd folder, dvd image, or something along those lines. Ive also seen options like save copy to hard drive, safe mode burning, etc... It will then put your finished project as an exzact copy on your hard drive. Then when you want to burn it, you should be able to select, burn previously saved movie or something close to that and burn with out waiting for it to make your movie again.
 Or you can use a cd/ dvd recording program like Nero. If you saved it as an .iso file or .img file you select burn image file, and select the previously made file. If you save it as a dvd folder (like it has a video_ts folder) you just select to burn dvd video, and drag all the files in the video-ts folder to the video-ts folder in your recording program.