pHEnomIC

I am gonna be doing some touchup work with duplicolor tomorrow. I have significant work to do on my 1/4 panel and while i know it isnt a long term solution i just want to get some paint on there.

Anyways, what are some tricks to blending paint? I was extremely surprised when the few small spots i did matched perfect. I am going to be doing a larger area so i may need to do some blending but the paint i have should be able to be blended. Anyways, i was thinking sand to bare metal clean it up good, prime and about 5 coats and then sand an inch out of what i painted, clean up and prime the whole area and then 5-9 coats. I can then buff it once it dries completely. Will my method work or should ido something else?