These techniques I am about to explain to you are based on my observations on how my videos require more work to match that of what I see on the big screen in the move theater.
1. Set your camera to 24fps. To be honest this is probably provides the smallest benefit of all the items I am going to tell you about. Most people can not tell the difference from 24 to 30 fps, this happens more on a sub-conscience level. The main reason I shoot at 24fps is not the look, it is because it creates smaller file sizes for me to edit with.
2. Shoot with a shadow depth of field (large sensor) This can be done with DSLR with large sensors like the 5D T2i and the 60D. This I think is the item that provides the most benefit of all the items I have. Not every shoot has to be this way, but just watch and film or good TV show and you will see super shallow depth of field used over and over.
3. aspect ratio, this is the second most important. Normal people notice this right away when their TV is letter boxed once the movie starts. This is a dead giveaway that this is a film.
4. Shoot in 720p or higher, to match film you are going to need all the resolution you can get. However many will not notice that much difference between 720 and 1080.
5. Use a tripod, a monopod, use a rig on your shoulder, most important keep it steady unless shakiness adds to your story.
6. Use a slider or a dolly at least a few times to reveal something
7. use a gib, most films use an establishing opening shot and most on done on some sort of gib where the camera glides up from street level into the trees.
8. Shoot flat and then Color your video in post. The in camera settings while very good can be a bit over saturated or have too much contrast. There are many tutorials on how to color your video to look more like a block buster.
9. Don't zoom while filming, instead shoot far away then close up with a cut between shots. Zooms are super fun on a camcorder but I would bet that most film crews just own prime lens and don't use any zooms unless it is a very special shot.
10. This last one has nothing to do with video, but if you audio sounds like crap because the mic is mounted on the camera, or you are missing background music that completes the scene or missing foley noises of an important event, even if you did everything else right on this list the audio which 50% of your video will not look like film.
11. Tell a good story.