I been a filmmaker/designer for over 6 years. I do mostly on location design, which i'd call more like interior designer rather then set design. I would say i've done a few set designs on actual sets, but i don't recommend it if the company does not have a budget to make it not stand out as a set. Any ways back to the question (in the title) which do you prefer or do most of: set designs or on location design? Which do you prefer or find more gratification?
Location.