I just read Julie Morgenstern's Never Check E-Mail in the Morning - not my favorite book, but I very much liked some of her points. Here's one of those.
Perfectionists tend to evaluate everything they do in one of two grades, either perfect of a complete disaster - there is no in-between. This approach is demoralizing, depressing, and unimaginative.
A lack of perspective leaves perfectionists feeling crushed by the weight of their own expectations. . . .
Perfectionism has its place - you can and should hang on to your eye for excellence - but apply it only when it really counts. In the unique stresses of today's workplace, every perfectionist . . . needs to undergo an evolutionary adjustment, and develop what I call selective perfectionism - the art of deciding which tasks need to be perfect, and which ones can just be good enough.
[poster from Despair, Inc.]