Sometimes when I have an idea in my head, I'll do a "mock up" on my face, meaning I sloppily apply the basic idea of what I want to do on one eye. In this step it's not about perfection and precision, but achieving the basic outline of what I'm going for, trying to replicate the vision I have in my head.
Here's an example of something I threw together tonight, this took me about 10 minutes.
As you can see this isn't perfect, my lipliner is all over the place and the blending is not precise. I used dirty brushes that I just wiped off on a paper towel, I didn't sharpen my pencils. When I do a practice run, it's not about getting a perfect look, it's just to get an idea going to see if it would work as an entire look. You can see that the cheek doesn't work at all with this, it's actually from the makeup I had on today which I just quickly wiped off beforehand.
So I'm sure I will refine the look a lot before I decide to film a video for it, I might add or change things. But I thought I'd give you a quick look into the thought process that goes into my videos. I don't do this for all my videos, but for ones I'm not so sure about, or when I'm trying something different. I find the looks I do a practice run for, always turn out better in the end, and the additional practice helps to refine my skills.