This is not so much a "method" as an approach--to learning Spanish the natural way, like children learn it. Making judicious use of material available in your host country: comic books, songs, films, television, the internet.
There low-cost materials are suggested, all available online or near at hand. Learning by reading books or newspapers is very difficult. Reading childrens' books and comics is easy and memorable. Song lyrics stay in your head forever.
Download this for free, pick up the recommended paperback dictionary and one-sheet grammar guide, get a notebook and start learning the quick, easy, natural way.
CABO BOB is famous in Mexico.
His little yellow book, Mexican Slang 101 is a classic, with over 100,000 sales in paperback alone.