I dont have a tutorial, but I use an oil based primer I got at Ace (called Rust Stop), let that dry at least 24 hours, then coat with fingernail polish, with a final coat or 2 of 'hard as nails". I have found this to be very resilient on both hard foam and soft closed cell foam. A lot of the sally hansen colors have some sparkle to them. Frankly, a lot of folks dont use any paint and they prob catch fish as well as the painted ones. I made one from alternating black and yellow foam sheets zap a gaped together and it looks fine w/o paint. Of course, those chartpak markers from j stockard do fine, as well as sharpies......
just my $0.02....