This is a great question, and I can tell you from experience. I use debt leverage. I started because in 2006, a "friend" of mine gave me the saddest story of his life about how he needed to sell his house to stay alive and save his marriage, and all of the humanity! Since, at the time, I was into saving lives, I bought this house at full market value, paid all closing costs (remember, he and all of humanity was at deaths door), and purchased a mold infested one bedroom one bath in a shady neighborhood. For 5 years I could not sell it, and I was always upside down on rental income/mortgage. I went through a lot of tenants. A LOT! For 5 years I suffered a loss every single month. So in 2011 I just dumped my savings into it, got rid of the mortgage, made it as nice as possible, and found an awesome college student who loved the house. She stayed for 3.5 years and was never late on rent. When she moved out, I owner financed it and sold it at a "break even" point. That house was a very expensive lesson, but I think it was worth it. It taught me that I want to deal with a specific type of tenant, and own specific types of houses. Side note: I traveled a lot for business, so the house did not get the attention it deserved.
So onto the financing. I finance all houses with 20% down, in very nice neighborhoods, and make sure that they cash flow. Yes there's a risk, but I cut that risk substantially by getting extremely nice houses in a great school district and I do not make a decision without my property manager. We cruise neighborhoods often. With her there, she won't let me buy a house because "I can make this work". The house must fit our formula that we have created. If it doesn't fit, we move on to the next one. Obviously, this process is painfully slow. But I know the neighborhoods, and always make offers as soon as houses foreclose, or go for sale.
I am financing 3 properties over the last 3 years, and all of them have been amazing experiences. All of them cashflow, they are great write-offs for taxes, and our tenants pay on time and have made the houses their homes. I love debt leverage, because other peoples money is helping my wife and I accomplish our goals.
Since I have moved, I am creating a new formula to follow and trying new and creative ways to finance houses, and looking to build relationships with investors, property managers, and realtors in this area. I am not claiming to know enough to mentor, but I know what works for my wife and me. If you ever want to discuss opportunities, I'm up for it.
Never stop learning!