Facebook prepares you for their own interview, they give you study materials, references and plenty of tips. They hire strong engineers and they want strong engineers to hire.
Make sure to study Hackerrank.com – algorithms, data structures, tree traversals and the like.
Practice by interviewing at other companies. The process and the skills translate from one company to another quite seamlessly.
This is very important and a step that I may not have done: actually want to work there. This is important.
You need to be passive in that you can’t show that you’re desperate for a job, but you need to show them that you want to work there.
Load up on a lot of patience. This might be a slow process, it might take a while. There is a guy who interviewed at Amazon 8 times and the 8th time he “almost got it.” A recruiting company said they think it takes 4 weeks to get a job, on average. Don’t believe silly things like that. It takes a year, multiple years of focus to get it. Of course, we’re talking about top IC (individual contributor) positions at top companies.