I use Farecla G3 light cutting compound with a splash of water added to make
a toothpaste type consistency. Another splash of water on the wing with the
polish before I buff with a foam buff. Goes on consistently. I then use a
polish like Nu Finish and polish with a lambs wool buff.

I finish sanding with 2000 grade, spanwise. Comes up like a mirror.

Repairs are done by wet sanding the area with 400 (care not to sand through
to the primer outside of the repair area).
If repairing scratches by 'layering in" PU (for small chips or small
scratches), remember that PU will shrink to half its size when it dries.
Generally used for on field repairs.

If the area has not been prepared properly, you will get a shadow/watermark
around the repair when you sand it back.

Chris