Quality Spray paint, paint pens, airbrush. just clear coat over it after you are done so it wont come off as easily. My brother just did this for me last week on my lost rocket. stoked to show it off.
Ya my bro did my buddy's surfboard last year. Same thing, paint pens and clear coat over it. We didn't know how long it would last but it's held up pretty well.
i have been experimenting with a bunch of mediums. everything from spray paint, to air brushing, to paint pens. im currently on a sharpie kick. as long as you clear coat your work you should be set.
I use the krylon airsol can stuff you can get at Walmart. Some people aren't fans but it works great for me