From what iv'e seen, you have to turn it really fast for at least 70% of the video whilst saying it's either buttery or crunchy. Force the cube to cut a ridiculous amount which should never really be all that necessary. And then finish it up with a summary of "It's pretty good" or "It's not that good".
But no seriously,
1. A first impression (Your personal first take)
2. specifications (Weight, size, does it have magnets... You know the general unbiased details of the puzzle)
3. Take it off camera, use if for a couple of days with different tensions and different lubricants
4. Come back and talk over some footage of you solving and go over your final key points. (M slices, outer slices, magnets, which lubes work best, would this cube be viable for one handed, two handed, BLD/MBLD?)
5. Make a pro/con list and your final recommendation with the comparison of the cubes we all already know and love (GTS, Gan and valk).
Things for the description
1. multiple places the cube can be bought
2. Some random link in there leading to a cool cubing thing you've seen this week (I don't know just something interesting i guess).
It's also nice to remember although a large majority of people mainly do 3x3 with CFOP. Some people use other methods or a multiple of methods. I like BLD and stability coupled with general smoothness is what i look for, but when i'm just doing standard 3x3 i smash some DNM in my valk and go nuts with it. just another thing to keep in mind.