I would say the really important thing is to always have something showing.
I mean, you could spend ages and ages on a data driven entity system, with deferred rendering and really high FPS, and all that. But chances are you'll get bored of having nothing to show, and give up. Whereas, if you first try getting a few models on the screen, move them around, and go from there, you'll have a much better chance.
I think the first is bottom-up development; working from a framework up to the actual content, and the second is top-down; working from getting some content and building up from there.
A little point, but something that really helps.