There is no right or wrong, kinda - as long as it makes you happy and doesn't hurt anyone. Think about a cloud. Just float around and be there. Maybe there's a happy little Evergreen that lives here. You don't have to spend all your time thinking about what you're doing, you just let it happen.
Only eight colors that you need. I really believe that if you practice enough you could paint the 'Mona Lisa' with a two-inch brush. Here we're limited by the time we have. Just think about these things in your mind and drop em' on canvas. You got your heavy coat out yet? It's getting colder. You can spend all day playing with mountains.