Well, as you know, black is the most difficult. My color is fairly easy. Not as easy as my other two vehicles which are white.
In any event, I have tried so many different products through the years, and I know everybody has their own loyalties and favorites. Currently, I use a clay bar on the areas I think I need it (plus the windsheild) , but not necessarily the entire car. And my current choice of polish/way is a Griot's product. It is a one step cleaner, polish, and paint sealant. Usually a product like that, that tries to do too much at once, fails. In this case though, it works for me. After a harsh Michigan winter, the water still beaded it up like it should and the car came through the winter unscathed again.
I used to use Zaino products...... A multistep process.... I would use their all in one cleaner/wax followed by their Z2 show polish followed by their clear seal.. Honestly, the Griot's is less expensive, and way faster for me. I do the full detailing in November before the winter and then in May before the summer. In between, I wash the car every week either at a no touch drive-through carwash, or a local drive-through hand wash place we are lucky enough to have.
Again, everybody has their loyalties and if you ask each person on this forum, they will probably tell you why they think their products are the best. I just know what works for me. If I had a black car, I might do a little more work (like my former Zaino 3 step regimine).
I also use a clear plastic polish on the taillights and I used Trim Shine, a Stoners product, on any black trim.