Buy a house to live in. The best low-down financing is always for owner-occupied. Plus, you gotta live somewhere anyway, right? Then, after a couple of years, buy another house to live in and keep the old one as a rental. Rinse and repeat every few years, buying a new one to live in every couple of years, and keeping all the old ones as rentals. The renters pay your mortgage payments which will eventually pay off the houses. And with rental properties, all of your expenses that exceed the amount of rent collected are a tax write-off (not a deduction, a write-off).
After 40 or so years, you will own quite a number of free-and-clear homes, that have been paid for by other people, that should have greatly appreciated in value, which you could sell or borrow against (and if you borrow against, the renters keep paying) to finance your retirement.