The needle stop I used in the beginning. Basically as a training tool.
I'd screw it in to l it touched, then push down the trigger. Then uscrew it ever so slightly.
This was mostly to see how very little trigger movement I could use for a thin line.
The Mac valve was basically left open until later when I need very low pressure. Because that little compressor goes on and off way too much when you get regulating down to using 10 psi. Best to regulate 15 and tune down from there, it's mostly useful when you get into higher reductions.
My favorite is about the incline of a drawing table and I often use both hands for detail work. Used to let my pinky touch to keep a steady distance. Sit as a often as possible.
Standing works great if you're going for a mainly freehand method on large pieces or going for t-shirt style work. It makes it easier to do fast , long movement.