Careful with cleaners however and make sure you get any of the cleaner residue off or else your paint will start to bubble an such. dont spray too thick like 69GWC said. Use a primer to be able to fill scratches and use very fine grit sandpaper to make it smoother than a babys bum.
Then spray with even coats starting on the edges first ( cause they can be the most difficult ) and just fill everything else in. Oh and make sure you use quality paint, ive gotten away with using walmart paint with some pretty decent results but when i get dollar store paint it doesnt seem to work as well. Duplicolor is probroly one of the best spray paint cans you can get. Nice even spray pattern and you get a decent amount in the can.
Follow all of these steps and soon you can tackle a job like painting your truck. I did mine and with all that i learned from using spraypaint i got the skill down and had no runs, orange peel or tiger stripes.
J8ust keep practicing and you will get the hang of it
