touch up paint ? (for experienced)

[12v]

Hey guys, i have been experimenting with touch up paint on my car. I have a single stage white paint job on my car.

After about 7 tries. i have finally found a paint that actually matches my car almost perfectly. my problem lies in the blending it into the original paint.

first of these are tiny spots that i have touched up. they are nickel sized to... well cant think of anything, but some of the spots are about 3 square inches.

i went through the long process of making it worse before i could make it better. (had no idea you could take some automotive lacquer thinner to remove touch up paint first off.... ended up wetsanding to much and making my problem worse). so my tiny spots ended up turning to big spots of grey primer on my car. lol no problem for me because my best friend paints cars for a living, i could always get it repainted, but that is not what i want, or my goal for this situatuion period.

My problem that needs a solution.... this one is mind boggiling even for me. Unfortunately i have large painted areas, unfortunately even more they werent sprayed on, they were brushed on. I have tried the langka blob eliminator, but noticed it ended up either spreading the paint onto the good surface, or just eliminating the touch up paint period lol. So i just need to know a good sanding technique, spot sanding if you will.... sanding blocks are to big. and i have about enough touch up paint to redo one spot, so getting more paint and spraying it is out of the question... im stuck with brush strokes that need to be blended in. any and all advice would be greatly appreciated.