Some of this is the general how - to, a small touch up spot will require a more direct approach on a single spot, so bear that in mind.
Let some 2000 grit paper soak for at least 30 minutes in a bucket of water with some car shampoo added for lubricity. Don't skip the soaking step or the paper will be too hard and cause side cutting etc.
Use a small foam block (A foam block as a backer will cut more evenly than your hand), making sure you fold the factory edges of the sandpaper under itself so that no factory edges are visible. This is important because a factory sandpaper edge WILL cause side cut scratches that will be too deep to remove.
With LIGHT pressure, sand in perpindicular strokes (at 45 degree angles to each other ) and DON'T sand in circles, because it can wrinkle the paper and cause a cut/scratch. Keep the paint area soaked and wet, dip the paper back into the bucket each pass or 2 to rinse it. Every few passes, dry the area with a squeeqee or towel and observe the area. When you start to see progress, slow down. You will also see orange peel start to dissappear. It appears as dark spotting in the hazy sanded area. Once the orange peel in the affected area is gone( or in your case, the touch up is leveled), STOP. You're treading on thin ice then. Make sure you do the pheripery of the area a bit too or you might find the spot too obviously free of orange peel etc. making it look conspicuous to the eye. This isn't always the case, but it can happen on larger areas such as a long scratch touch up.
On small areas such as chips etc., you can use your hand against the paper if need be, but on larger areas, never stay in the same pattern, or rub in one spot too long or you'll see the indent of your fingers (believe it or not). This is a general rule though, since you pretty much are going to be sanding the touch-up spot, you have to sand that down specifically. After you achieve what you want, you have to first compound then polish the area. I use 3M Perfect-It III Rubbing Compound , followed by 3M Perfect-It III Machine Glaze, and sometimes finish with an even finer swirl remover polish (Meguiar's #9) on dark colors.
You could use 1000 grit then 1500 grit too, but I always feel the beginner should start with the lesser grit papers so you don't remove too much paint at once. Remember ; automotive paint is ~2 MILS thick, or the equivalent of the thickness of a baby's hair (~50 microns). In your case, be careful that you initially sand the paint touch-up more than you sand the paint around it, at least till it's near level.
I've wet sandsed show vehicles, been doing it half my life, so most of this I have to think of how to tell you, and hopefully it will make sense. Good luck. Patience pays.
