If I want to do a bigger illustration, I like to prepare for it. In order to do that, I research the planned setting with sketches on paper or digital. After that,  I look for nice references to help me with the colours and lightdirection or which help me see my initial idea in a new light.
after that, I do more refinded sketches from my basic scribbles, just like those:

Here I establish the basic composition and value distribution. In that stage it is very easy to introduce changes. In the case of  this illustration, I had the scribble of the warrior on a older batch of scribbles. Since it  was a natural fit for the idea, I used the scribble and copied it in the tonal sketches. In a production sense this was a neat timesafe. One of these will be made into the final Illustration.
The other concepts don't go into the wastebin. I keep all of my scetches and scribbles, since they might be the perfect base for another idea.

When that part is set, I sometimes put a bit of design  work into the characters in the scene. Especially when I might use the same character multiple times. In that case, I create a charactersheet to use as reference. with that, I can make sure the character will look the same in various illustrations an in case of armor or weaponry, I can design them in a meaningful way I.e : working armor and weapons which provide actual protection from foes and elements.

In case for this illistration, this will be a full body shot of the character, armor and face, as well as some details. Here I only show a bit of it. If I plan on using the character more regular, I put more work in all the details fo his clothing, belognings, front and side view and some action-scribbles and gestures.

Next step would be a some basic colour blogging on the chosen tonal scetch and, depending on chosen stlye, a clean lineart or the start of the final illustration. Maybe I'll do a livestream or recording for this illustration.. or both.. :)