1. Buy can of spray paint - pref a colour that you want to paint the board.
2. Prep board surface - wet/dry or 3m pad, wipe down with clean cloth & prepsol.
3. Shake can - only if you want the paint, not the thinners to coat the board.
4. Point can at target - not at face...done that, not nice result or good for eyes/lungs.
5. Press nozzle on top of can - self explanatory.
6. Take time to overlap each pass & finish with a diagonal cross-coat - getting tech there, sorry.
That's my advice - although I'd generally use a sprayable polyurethane & spray equipment.
Agreed sailhack - rattle cans do a very poor job on a large area (lines in it, overspray settling on nice glossy bits you just did all nice 
)
If not spraying with real spray equipment, closest you can get is a foam roller - it can do a really good job
I'd add point 2.5 - sprayputty and resand with wet n dry.
Cool, nothing too complex then
I was thinking some sort of creative spray design over a white base, so over-lapping lines from a spray can may not be too obvious. Finally, should I seal the finished "design" with a clear enamel lacquer?
Cheers for the tips.
There was a utube video posted on Seabreeze of a bloke painting the hull of a boat with a roller. The finish was fantastic.
).
Interestingly, last time I suggested to those with no spray gun they use a foam roller, I got red thumbed to bejeezus. Suddenly it is a good idea 
I have seen a show car done with foam roller and 2K marine paint, 16 coats compounded and buffed and it rivalled the best spray jobs you've ever seen.
Phil, for cheap just rub it back to nothing then do a foam roller job.
All good Sailhack. No clear coat then. Sounds easier and less fiddly. Though you may have to run me through steps 3-4 and 5 again...
Mark and Karl, seen a boat done with a foam roller too. Bloody amazing finish- as good if not better than a gun. I sprayed my last boat with epoxy enamel, looked fine, never looked like peeling etc. A board with a foam roller shouldn't be too hard. Spray paint for the fancy design.
Cheers for ya help.
What about grip ?
I am preparing to apply new coat ( tansparent or white ) to improve grip on my older board. I bought event extra quick solution called " Lucid grip" then realized that -intended for skate boards - and broken glass filler could be to abrasive for bare foots.
How to do the best new grip coat then ?
For bare foots ( since for boots is completely different story)..
Do you own a spray gun and air compressor and a sander? or can borrow or steal one?
).. If you have ants nearby you will possibly find them all over your board, but once dry and the sugar has dissolved, the crystal-like edges of the sugar particles leave a perfect grip, depending on the use and paint quality - should give at least 2 yrs grip (mine lasted 4 and still going).
Regular sugar is like having 40 grit sand paper for deck grip. Plenty of grip but wears away skin on ankles and knees. Caster sugar still gives good grip without being as abrasive.
Yeah sailhack walks barefoot on the bitumen in 45deg, all 25km to the beach, carrying his gear.
And back.
one of my friends owns his own panel shop , He resprayed my isonic , we rubbed it back with 1200 until nearly all the original paint was gone , then he gave it a light coat with 2 pack , then 3 clear coats very shiny finish, Made the board weigh 6 grams more Sweet F/A , On marginal days it does feel alot faster , when the wind is up and very consistant there is no difference
I am gonna give "monster paint" a go for re-gripping my old mistral, clear spray on grip, the new hobie shop at caloundra has a tin put aside for me, will let you know how it goes.
'Monster grip'.....good stuff but be sure you don't lay it on too thick, it'll peel.
several thin coats is the go.
Also it doesn't like to go over nitro cellulose putty, peels on that also.
Good and grippy and not abrasive, can cover several boards out of one can.
