you do realise you're talking to yourself?
On a different note mate, what airbrush are you using? I seem to remember that you got hold of an H&S double action Evolution? If so, I reckon you could get a finer demarcation line (feathered edge) between any two colours you're spraying, I assume you're using acrylics as most ppl do nowadays and even I'm slowly going over to them. If so, what sort of dilution ratios are you using and are you using matt paints?
I'm still using the Evo 2 in 1 with a .2mm nozzle/needle. But I have some trouble controlling the pressure - that's a completely freehand result by the way, I didn't faff with white tack and masking.
I use the Tamiya mini acrylics and start with a single drop of X-20A in the paint cup to lubricate followed by however much paint. There's no science to it. I just make sure I have thinner in the cup prior to adding the paint otherwise it clogs like a bitch. I follow the tutorials on the Pro Modeller site and it seems to work for me now.