for me its doing it how we used to do it, although it seems i look at things differently now. for instance, when i was younger i bought what i could afford. i liked to have a mix of components x lite this, hope that, use the other. i also used to bolt all sorts of pumps, bottle cages, crud catchers dcd's etc to my frame.
today my main retro build is mostly colour co ordinated, i have treied to use a lot of pace parts and the frame is un cluttered. there are many references to classic cars on this site. a lot of classics (vw's spring to mind) are done in a retro style but in a way that would never have really happened. for instance there is a movement known as resto cal. the idea is you take a restored stock beetle, throw lots of chrome at it and slam the suspension. how many beetles looked like that in the 60's? none.
i love all retro bikes. pristine rebuilds, fancy paint, clunkers thrown together with what ever is lying around.
my idea of a perfect retro bike changes daily.
basically, to coin a popular phrase, if its old skool, its in