I bought some custom graphics from a local sign shop several years ago. The owner was a super cool fellow that'd gotten into the trade doing race boat graphics and the expanded to all manner of vinyl signs and stuff.
He had an airplane inside doing letters on it when I arrived! LOL
Anyhow, he had me pull the bike in on his carpeted(!) showroom and proceeded to do the left side of the fairing of my Honda while I watched.
Done, he switched sides and said, "Your turn."
The next thing I knew, I was following his instructions and actually got it right. Could I do that again? Don't know, but a spray bottle of water with a single drop of lemon Joy dish soap was used to thoroughly lubricate the work area and the back of the vinyl to get it in place. As for curves like on the gas tank of the SCR, there weren't any. So, I don't know of any trick there except maybe warm the vinyl with a hair dryer to help it conform to the shape.