Happy to share. This is my first step, taking an image from the www and making it to scale.
I measure the kit, not all kits "are to built scale", some are bigger, longer or wider.
I use Corel as my graphics program, any you can enlarge or reduce will work, Corel = $$$.
I have Corel because I do my decal artwork in it for printing...... I digress.
After making the image Kit size, I then trace the camo pattern with a White hairline in Corel,
easier to see when printed. Then after printing, section by section I cut the patterns out
with a fresh blade.
I use a piece of clean glass, I then use Tamiya washe tape, tape an area a bit oversize of
the paper pattern section on the glass.
I trace the cut pattern onto the tape with a pen and cut the Tape to the pattern. I leave
about 3-5mm, 1/4" of tape to wrap over the edge of the wing, to seal the edges.
After a couple are cut I will apply one that gives me the best edges to locate the mask.
In the case of the lowest wing tip illustrated above, the one under the roundel.
Then I use the paper of the darker color to locate the tape mask above it.
I just march around the fuselage the same way.
HOWEVER........... not all the masks line up, or are vague as to how they wrap around curves.
So I tend to cut them apart, no more than ONE cut, apply what is obvious and fill the gaps
with 1mm wide strips of tape to complete curves, then fill the gaps with the cut scraps.
I have to do this for the Mustang, perhaps today, and will try and do a sequence photo shoot
of the process.
It's not the difficult really once seen how it's done. The most difficult part is pens don't make
a very dark image on Tamiya tape!!!!
Hope this helps. But......... I Never cut on the plane!