My brother, a custom painter, has used this technique with great success.
If he had a customer who'd used touch-up paint and left a raised "blob", he's use a new, single edged razor blade to carefully "slice" layers of the blob off, don't try to remove it all at once. After getting the touched up area fairly level, he'd use progressively finer, wet/dry paper to level the repair with the surrounding paint. He's then buff, polish and wax the repair.
His way of repairing chipped paint...
First, don't use the brush that comes with the touch-up paint. Get a book of matches, pull one out and dip it very lightly into the paint. Dab a thin coat of paint into the chip, keeping within the chip, try not to overlap onto the undamaged area.
Repeat this process until you've built the paint up to the level of the surrounding paint. Let the touched up area set for at least two weeks, the lightly sand with 500, 1000 then 1500 grit, wet/dry paper. Use a spray bottle with a drop of dish washing liquid to keep the paper from clogging.
Buff with a white polishing compound, polish with your choice of polish, then wax.
It's tedious, but the repair is almost invisible when done... Hope this helps someone...