Beth,
Unconventional financing breaks down into several categories, but the most common is Hard Money Lending.
Typically hard money lenders will want to review a portfolio of your past successful projects and read through your project cost estimates in detail. They will look at the deal you found and decide for themselves if it has high potential, marginal, or poor. The more risky the investment, and the less experience you have, the higher rate they may charge you. Hard money lenders lend mostly in the short term (6 to 36 months) and charge interest rates around 12-15% plus points for even the most experienced investors. You’ll need to establish a history of successful projects and a relationship with a hard money lender before you can expect the best financing terms.
I know that might seem intimidating, but you can get their quicker than it sounds if you are knowledgeable. I recommend the book “Investing in Real Estate with No (and low) Money Down by Brandon Turner presented by BiggerPockets. It breaks out several other kinds of ‘unconventional financing’ that may be useful in your situation. In the meantime, try and find a local BiggerPockets meet up in your area and start networking with other investors. Most of them will jump at the opportunity to help mentor someone.
And always remember, in the world of Real Estate, the deal of a life time comes around once a week.
Good luck!