Section by section, I swept up any large debris (such as from under a couch). Then I vacuumed the section. Then I cleaned it with Bona cleaner. I cleaned the sections again with a deep cleaning Bona product. I let it dry completely.  I used a special "sponge" that I got a the hardwood dealership.  It turned out fantastic.  It's got to be super clean before you apply it.  And work in sections.