A nice tip. Use about two different shades of each color to give it more depth. Clean gun between color changes.
I'm no pro so I do not say that my ways are the best or that I can paint well I'm far from it!
I like this hobby but not more than I love fishing. Hope this helps a bit. Have a look on you tube for some ideas and some video tutorials. this is the basic step to flames.
Good luck and happy painting.