make sure your chips and scratches are fully cleaned out ie with ipa or equiverlant, once you've got that done you can add the paint, iether use the brush that comes with the touch up or a cocktail stick to carefully drip a blob into the chip, you want the paint to sit proud of the whole in like a dome shape, once you done all the chips leave it to dry for a day or two,you can also aid the drying with a hairdryer if your carefull enough, then get your wet and dry paper and a block and rub the top of the domed paint very gently, going from side to side and very small circular motions until the dome part of the paint is flush with the car again, keep stopping and checking your progress so you dont take too much off,
when your happy with it wash the whole area again with plain water and double check everything, then get a finishing pad and finishing compond and polish it really gently until you return the lustre to the finish. keep in mind the paint may still be a bit soft the longer you leave the paint to harden before you rub it back the better, and theres less chance of it lifting out when you polish it.
I'm about to buy myself a DA and some touch up paint and have a go at doing this myself. I have my brother's M reg Fiat Uno to practise on, but the only this im nervous of is the wet sanding.
I've watched someone do it on a demo day at a BMW show and i think i'll be ok, but have you got any tips?