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.
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.
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