A lighter weight, hot press paper is more absorbent. Sometimes I have to stretch the lighter paper with tape around the edges to flatten it after painting. I adjust my handling of the paint to suit the surface. Gouaches are easier because I can work faster and more spontaneously than in oil. The occasional dribbles are controlled to the extent that if I don't like them, I paint them out.
Good art is whatever's got class.
That's something you work out over time. Usually, this process happens in the privacy of the artist's or artisan's studio.