By smoothing out the paint I mean sanding it. When the paint dries, it has a tendancy to be a little rough and orange peelish. Running over it lightly with sandpaper removes the peices of grit (most likely small dust particles). The paint is tacky after a few minutes, and I wait about 10 minutes between each coat, putting on 2 coats and then sanding/smoothing. As far as the bubbles, if you let the paint tack up for a minute, and go over it again really lightly with the roller, it will smooth out beautifully and level itself.