What are the tricks to precisely locate decals on scale-model planes?

[t_tail_boy]

I might have waterslide decals for a jetliner, say a Boeing 727-200 model in 1/96 scale. I want to make sure decals representing doors and windows, for example, or in the proper location and are applied to the fuselage straight, not cockeyed. They can't be too high or two low on the aircraft body not too far forward or too far rearward.

What are some methods advanced scale modelers here use to get authentic positioning for decals rather than just looking at pictures on the box or the kit instructions and using your "calibrated" naked eyeball?

I'm sure on full-size airplanes there are standards for graphics locations such as pinstripes, name logo and registration numbers. I'm sure templates and strict measuring instruments are used. Neatness counts.

 

[Quaralane]

I'll be honest. I've mostly relied on my decal layouts and the mk1 eyeball

 

[dogfish7]

Yes. Photo reference works best for me also........... give or take a rivet.