I bought some stencils from Anarchy models KS last year.
I finally managed to test them out and this is the result:
I should have been bolder going over the edges of the model with the stencils.
I'm a complete novice with an airbrush, but I found the stencils pretty easy to use. There was a bit of an issue with paint lifting when the stencils were removed, but that was easily fixed.