Map the frame
Sketch the main tubes and wheels from the side. Identify broad areas that can carry colour and narrow areas where a small accent may work. Check the design at the scale of the whole bicycle.
Test a limited palette
Compare two or three schemes with different accent proportions. Think about how the frame, wheels, and accessories read together rather than decorating every component independently.
Prepare carefully
For physical refinishing, follow the bicycle and coating manufacturers' instructions and appropriate professional guidance. Keep braking surfaces, bearings, identification, and functional fittings free from experimental coatings.