As a bonus, he even itemized lists to simply concepts for people like me. Here's his list of the Five Principles of Innovation:
• Begin with an analysis of the opportunity.
• Analyze the opportunity to see if people will be interested in using the innovation.
• To be effective, the innovation must be simple and clearly focused on a specific need.
• Effective innovations start small. By appealing to a small, limited market, a product or service requires little money and few people to produce and sell it. As the market grows, the company has time to fine-tune its processes and stay ahead of the emerging competition.
• Aim at market leadership. If an innovation does not aim at leadership in the beginning, it is unlikely to be innovative enough to successfully establish itself. Leadership here can mean dominating a small market niche.
Source: Drucker, Peter F. Innovation and Entrepreneurship
*Bonus! Check out Drucker's 7 sources for innovative opportunities