[gambiting]

Like.....absolutely surefire? I can only think of one - borrow $$$, buy a large warehouse/commercial building in a popular part of town, pay it off within 5-10 years either by renting it out/running a business that at least pays for the loan payments, then once it's paid off just rent it out - if it's large enough you will easily get residual income of $5k/month or more. That's like the only guaranteed way with >90% chance of happening. Anything else is a much larger risk and depends on you knowing how to run a company.