Finishing your weld?

[Ricoch3T]

How many of yall finish your welds when doing floor pans or splicing panels together?
If you do what is the proper technique for doing this without getting the weld or metal too thin? I've seen some people finish butt welds and such that look like they didn't put a patch in at all and I've tried myself on some scrap metal but it seems to be too thin when I welded it when i'm done.