So, I somehow managed to pick up a small chip in my paint. It's only about 2mm long, but it goes right down to the metal, so I'd kind of like to fix it.

Is it just as simple as buying some touch-up paint from Mazda and applying it? Or is there some 20 step process I need to be following? (I kind of suspect it's going to end up being the latter...)

 

For something so small I would just use touchup paint from the dealer (alternatively, you can search for the color code and get it at autozone for far less $$)

 

For small chips what works best (as far as easy methods) is to apply touch-up paint with a toothpick. Use the surface tension of the paint to fill the chip. You may have to do a couple applications, as the paint contracts as it dries. If you use too much, you'll have to sand it, which isn't that big of a deal. Probably start with 800 and work your way higher and you shouldn't damage the existing paint much.
It won't look perfect, as you aren't using clear coat, but it's better than a rust spot.

 

using touchup paint typically just paints the metal the same color as your car. so you'll still see the indent where the chip is. unless like other people have mentioned you spend hours and build it up slowly.

hypothetically the best thing to do would be fill it up with paint. so that it is a little higher then flush. sand it down with 1000 or higher and even it out with the surface of the car. then polish it out (the 1000 grit will dull the clear coat until you polish)... If you want to go that hardcore lol.