One of the central ideas in "Nothing Down for the 90's" is the use of creative financing methods to purchase real estate without a significant upfront investment. Allen explains various strategies such as seller financing, lease options, and leveraging other people's money. These techniques allow investors to acquire properties with minimal personal financial risk, making real estate investment accessible to a broader audience.

Allen emphasizes the importance of recognizing and seizing opportunities in different market conditions. He provides detailed guidance on how to identify undervalued properties in depressed or stagnant markets. By understanding market cycles and trends, investors can make informed decisions that maximize their returns. This approach helps readers to not only survive but thrive in various economic climates.

Beyond practical strategies, Allen also focuses on the psychological aspects of investing. He offers motivational tools and mindset techniques to help readers overcome fear and build confidence in their investment decisions. By fostering a positive and proactive mindset, "Nothing Down for the 90's" encourages readers to take action and persist in their real estate endeavors, ultimately leading to financial independence and success.