Hi,
video certainly makes it look easy, but,
a person probably requires at least 3 skill sets.

1. Knowing exactly how one wants the style to sound, and also knowing which notes are allowable for the various types of style tracks. (Manual I beleive does explain what notes can be used.)
I've always sort of thought of styles as mini compositions.

2. The ability to play reasonably well, or it can become tiresome recording the same track over & over again. Some keyboards have better editing functions than others, so the odd blooper could be fixed without re-recording.

3.Working out the settings etc for the style tracks so that they play back correctly over the various chord changes.
Again the manual should cover that.

If the onboard styles aren't 100% suitable there is the option of finding a style that's pretty close to what you want and re-recording particular tracks to make it more suitable .
There's also the option of copying tracks from one style to another, or from variation to variation within the same style.

I personally don't record from scratch, I lack skill set no.1.
i don't know what I want till I hear it. haahaa hence I mainly convert , edit & swap around style tracks.

Skill 2 , I could get away with only because my korg's got great editing functions.

Working out Settings etc , I've spent a fair bit of time on, so reasonably comfortable with that one.

It's always worth reading the manual's section on style recording, you may be amazed at what can actually be done.