that's a pretty good tutorial on how to pound the hell out of a gas tank and make it look good. however, it is leaving out steps 10, 11, 12, 13, and 14...
10) have a few more beers.
11) break out and apply the body filler.
12)sand body filler to desired shape/plane. have another beer.
13)after oversanding the body filler, add more body filler to correct.
14)finish with glazing putty, which will sand to porcelain-smooth, but not before revisiting steps 11-13 and wanting to throw your gas tank off of a bridge.
note: numbers 11-13 are a numerical anomoly, repeating possibly infinitely, without actually becoming more "steps."
i'd post a close up picture of mine, but then i'd show the hack of a paint job i did. it'll get painted nice when i get back from tour in 6 weeks.