You can find inspiration anywhere in your every day life. If you're using printed sources for inspiration, be certain you don't use images too close to the originals. Your vision should be your own, otherwise you're not developing your own unique style. You don't want to be too similar to anyone else. Many people prefer originality rather than mass production products that everyone has access to, unless that's your goal. Money over originality, which is ok. After all, you're in business to make money, not sell wall art. Do what fits your situation.