Matt what is your main income....domestic or commercial? If its commercial i would keep it basic ...like a business card only 10ft high and 15 foot long! For domestic make it a rolling sign board of flashy grapics, contact details ,bright colours,flashing lights etc so when the curtains are twitching everybody in the street knows what you are up to and how to get hold of you. I hate the grapics on my van ...it looks sooooo tacky but it works!