How do you do your gaps and alignment?

[The WidowMaker]

ive done a lot of reading and watching of videos, but im still trying to learn the best way to gap and align panels. so far ive been adding metal with either a rod welded to the edge or just weld, and then grinding it back. i can get an even gap all the way down the panel, but im now looking at how to make the panel alignment perfect when sighted down the side.

so once i get the panel gap and alignment as close to perfect as possible (and i mean CLOSE), what do you guys do next? ive seen some who cover both panels and the gap with a layer of filler. then they block the entire seam, and finally cut the gap back out.

is this how most do it?

any better ways?

any good videos or youtube clips?

as long as you arent adding length to the door or fender or adding too much filler depth, i dont see how this could be bad.

any product better than another? rage, all metal????

Thanks, Tim