I usually start a very rough draft on my sketchbook, take a photo of it and place it as my bottom layer
Then I make the digital draft and run through multiple options on how I could make it work and look good at the same time.
After the countless digital drafts, I flatten every design layer into a single layer (but I always do keep a backup raw group layer just in case).
Then comes detailing, I usually don't like this part because I'm very meticulous when it comes to detailing but it's always rewarding seeing the output
Then a few more detailing done and voila I finally finished it. And that's how I usually do my drawings.