There are a few simple guidelines that almost always work.
If you use them your movies will be better.
-Vignette: Avoid in most scenes. Unless absolutely critical and even then use a subtle vignette.
The moment you start to see the 'egg', your vignette is too strong.
Use it so it's barely visible and only on the edges of your renders.
-Sky:
If your scene is comprised of mostly bright tinted objects (concrete for one), make sure your sky is at least a good tone darker. This will help the buildings pop. If your sky is brighter then your objects, your objects tend to blend away in the scene.
-Camera paths:
Use sloooooooooooooooooooooooooooooooooooooow camera movements. Slow is good. Slow says 'Im a professional, I don't need to show you all I made, I just show you the best of the best'
Fast never works unless you are doing a chase cam or a tunnel flight or so.
If you think your cam moves too slow, thats good. Aim for too slow.
-What to show:
Work with pans from a single POV, perhaps complemented with a little zoom.
Move the camera up and down, thats np but watch out when moving the camera all-over the place.
It's OK when this is a big scene and you want to convey the impression of a camera flying along a long path
but it's not OK when you want a camera flying through a maze of streets, hallways and rooms.
-Be carefull with colors.
Most realtime scenes work best when you try to simulate the lighting conditions common on a overcast day. If you go for a sunny day, don't choose the middle of the day when all is bright.
Desaturate your colors with a post-effect filter a little.
-Use Motion Blur, even if you think you don't need it.
-Better too light then too dark.
-Better too little SSAO then too much.
Last but not least: Keep your movies short. 30 seconds should do it.
The average human attention-span has long been expired by that time
Thats about it.
Hope it's got something worth noticing
