i find that rustolium is far superior to krylon. covers soooo much better and adheres better as well.
i dont scuff just wipe clean with some alcohol (if not i just clean well), blue painters tape and spray.
with that being said i dont expect it to last forever, if i wanted a forever paint job that would be a totally different story. and it wouldnt involve spraypaint at all.
if im doing a quick color change for a specific time of year or hunt (fall here in NY...yes my state sucks... but going hunting in the snow up in canada) ill take some sports grip tape and use it as a base.
then spray over the tape what ever colors or pattern i need and go at it.
when i get back if i dont like the camo or it doesnt fit my AO i just peel off the tape and im back to my original color, no stripping or scrubbing.
depending on the reason for the camo;
camo is about breaking up lines, the actual pattern doesnt mean much nor does the color...jsut dont use black.
not sure who ever made up the original woodland pants but there is no black in nature, and deep olive drab turns black when in the shade viewed through optics.
you take a really dark color set and lean it up against a tree in the shade, observe through a optic of some sort and it looks like a black piece of PVC pipe