First off just use Flotrol, no water, use a high quality paint and brush. When it come to semi-gloss or satin paint don't skimp on what you spend. But I am a little bias since I sell Ben Moore. Products that have performed excellent in self leveling with out flotrol is Aura semi-gloss as well as Waterborne Satin Impervo. But I am sure there are other great products out there as well. As far as ratio's go, many painters go by feel but there is information on the back of the flotrol container. Good Luck....I'm painting my doors tomorrow and I wanna cut back on the heavy brush marks. What ratio or percent of floetrol, water, and paint do you use?