Prior to submitting the video, watch it. Check for errors. If there are any problems or issues, redo it. Particularly with any of the items listed below.
Do NOT do blind submissions.
Signing Box
This is the area where most of your signs are conducted. Abnormally large signing boxes are usually reserved for the stage (encompassing massive areas above the head and sides.) Large signing boxes are used by those who tend to be more gregarious; and those that are somewhat conservative generally have smaller signing boxes. So, signing boxes vary. For the video work, your signing box should include your head, torso, and about a foot on each side.
For example:
This is ideal. This, not so much.
I need to see your hands at all times.
Prior to videoing, ask yourself: if I sign "father" or "baby," will my hands still be visible?
After you video yourself, check to see if there are any signs that are cut off.
Remember: If you can't see your hands, "I" can't see your hands.
If so, then you'll need to readjust the camera, or step further back from the camera, and redo the video.
Lighting
Good visibility is important, particularly in the deaf common. It is common for Deaf person A to ask Deaf person B to move so that Deaf A can see Deaf B better "move," especially if there is a light shining behind Deaf B.
If there is a light shining behind you in the video, two things will happen: your face will become dark and the light will be the central focus of the video frame.
The same goes for overhead lights. See examples below
Ideally, you want as much natural light as possible. If videoing indoors, then in front of a window is best. If using artificial light, make sure that they are positioned behind the camera. The more light you have, the better your chances of getting good results.
Backgrounds
I'm not so fussy about backgrounds. If you film in your bedroom and your bed is messy, no big deal. I care more about lighting. However, just to give you more to work with, especially when filming in doors, be aware that the lighter the background (white is ideal), the better you'll stand out. Dark backgrounds only work if you have LOTS of bright, hot lights (think professional studios), otherwise you'll end up being dark as well.
And one last thing on this topic, mirrors in the background is a major no-no. Any lights that are shining behind the camera will bounce off the mirror into the camera's eye.
Body position:
Face the camera. Look straight into the eye. If you are angled away from the camera and I can't see your hands too well, then your signs are not clear.
Clarity
Now that we got the lighting and background out of the way, let's talk about your signing.
Keep your signs crisp and clean. Precise. When examining your signs, ask yourself:
Is that the right handshape?
Is it in the right location?
Is that the correct movement?
Are the palms oriented (facing) in the right direction?
Is that the right facial expression?
That is, know exactly what you're signing. Any hint of uncertainty, or ambiguity for that matter, will cause your signs to become fuzzy, almost as if you're signing with your head in a fog. And it'll having nothing to do with the quality of the camera. So, know your stuff. See Signing Parameters for more details.