as an OCAD graduate ,  i believe its a real honour and treat for me to do a painting or drawing for a patron because i find the work very enjoyable , Most people provide an image and i scale it up ,very common is acrylic paints. I also have been asked for pencil and ink renderings ,Some clients need help visualizing concepts so they tote me around to meetings and i do sketches or working drawings , i have a mobile studio for on site larger projects ,