A lot of people start painting with rather cheap oil paints. When their mountains don’t come out like they want them the problem is not their technique but the paint itself!
Oil paint in its basic form consists of particles of pigment suspended in a drying oil and the Titanium White that Bob Ross uses is a rather firm and dry paint, meaning that it does not contain as much oil as other paints.
As mentioned above oil paints are made from pigment and oil, so to get our paint to become firmer we need to find a way to decrease the amount of liquid oil in our paint.