If you have a body shop supplier near you, you might want to see if they have a product known as 3M Imperial Micro Finishing Compound and another known as 3M Imperial Hand Glaze. I've used this stuff for 40 years or more and I've always had really good luck with it. Costly? Oh yes. But it will save you time and effort and as Jerry said if you don't have any orange peel, etc, you might get by with this. This is commonly used to knock down 1200 grit marks to give you an idea.
