Prepping shells

[eyeayen]

So whenever I've done this before I've been working in a bodyshop and had everything to my disposal. Now, about to start again at home, in my garage, I've sold all my old gear and was just wondering...

I know people say they don't bother but I've always lightly scuffed the inside of the shell I'm doing to give the paint a key to stick to with a used piece of scotch brite or something.

Does anyone else do this or am I just being to precious about it and wasting my time ?