Do you have a sketch of what you want to do? Meaning...what the flames will look like...I think it might help...
I am about to do the same thing, but my wife is MAKING me practice the design on cheaper items...oh well...another reason to pick up the brush...

I look forward to future posts, I am sure I will pick up some hints along the way...
I have never done anything except a solid color...but if it is bigger than working on you table, I would recommend a jig...more stable (I would think) hanging will probably work for large area spraying, clearcoating...but if you are going to be doing shading...