Some look like air pockets, some look like sand particles. Grab an ice pick and start probing. Air pockets may be from a contaminated surface.
Directions on a product are great when they work. These products are going to give simple instructions or most folk are not going to buy the product. Dawn is a good grease cutter. Many paints can't be shaken, they must be stirred. Regardless, until you figure out where you went wrong, this will continue to be a problem. A little sandpaper over the problem areas, a little probing with an ice pick, you should find the problem, then touch up from there.
"When I was younger, I could remember anything, whether it had happened or not." - Mark Twain