My first step is to always make a "sketch" in photoshop of what I want to paint, just so I can figure out placements of everything without damaging the paper in the sketchbook. Sometimes I do actual full sketches in digital, sometimes I just bash pieces from different photos or images like in this case - the point is just to figure out the composition before I touch the paper.

Once I have my composition ready I do my sketch in pencil, and adjust things from my wonky digital sketch as I go. If the piece is super complex I will print the digital sketch and use transfer paper to trace it onto the sketchbook, but most of the time I just sketch in a rough grid that splits the pages in quarters to help with the measurments and copy the rest just by eyeballing things.

For the actual painting I mostly use acrylic gouche, or markers + watercolors combo. The paper in this sketchbook is actually pretty bad for painting, but I really love the format and the marker pieces I have in it, so I just plan around the limitations. I know I won't get any good wet on wet painting going on, so I try and plan my colors ahead to avoid repainting one spot too many times.

I usually slap some random underpainting color on the areas I want to work on (like the purple under the black in the photo above), since it's super hard to judge values correcly agains the light page, especially if there's going to be a lot of darks.