All great advice. I just want to repeat … use PENCIL and PAPER first!!! Sketch, sketch, sketch and sketch some more. (okay, it doesn’t have to be pen and paper … pen and vellum, crayon and newsprint, marker and drywall … sharpie and skin. Whatever … but SKETCH!!!
I would suggest rewording “black and white” to “one color” because I have had clients think that means “black and white” like in photos which opens the door to 50 (or more) shades of grey.
Planning:
One of the best tricks I learned in school was to start by sketching really tiny pictures (because I always added too much detail). By starting off with a 2" area, I can limit the original design to something graphically and informational strong. All the glitter, glitz and… ahem, “pop” comes later.