I don't know what kind of answer you're actually looking for, but here's my answer. Warning: you're going to find it disappointing if you're the sort of person who has tried 50 methods in 4 months and is ready to give up.
No "method" has worked for me. I create Amazon affiliate sites. I make about $8k/month from them now.
I started my first Amazon site 4 years ago. I worked on it every day for about 2 years. I don't mean most days, or every week day. I mean every. fucking. day. Sundays? Yes. Christmas? Yes. New Year's? You got it. I still have that site. In those 2 years it made around $0 (it lost money because of hosting costs). In the two years since then it has also made around $0 also. I still work on it sometimes, but have given up on it ever making money.
But, while I was doing that, I ran across some other ideas for Amazon sites and started those. One of them really took off. I spent a full year working on it everyday and earning nothing before it started doing well. After a full year of working on it and making $0 it suddenly started ranking for some good keywords and shot up to around $4.5k/month over the next year. It still makes around that much.
I also started some other sites. None of them made any money at all in the first 6 months, and none more than $100/month until a full year of work had gone into them. Some of those stumble along making $100 - $500 per month now after a couple of years of work.
Trying to speed up the process of creating an Amazon site, about 2.5 years ago I invested around $5k in an existing site that was on a great domain but was really poorly optimized and making very little money. I was paying for the domain because I thought I could rank much faster with that. Again, I spent a year working on it before it started making any money, despite the awesome link profile. I had to create large amounts of awesome content because the links alone weren't enough to rank for anything very profitable for me. Those links together with awesome content does rank though, but it took a long time before it started ranking and making money.
I'm sure there are people who can do this way more efficiently than I do, but that's my experience. I'm a full-time phd student, so a side income of $8k/month matters to me.
So, long story short. There is no fucking method that is going to make you money. You're going to make money yourself by working on your strategy everyday. For me that means creating awesome sites with awesome content and then emailing thousands of people trying to get links. Other people probably go about it differently. But the method is that you keep fucking working on shit til you get it right. What else do you want people to tell you?