The best general advice I'd give is to dupe your picture layer, do all the spot fixing using whatever Photoshop techniques necessary (healing brush, cloning, smoothing etc).

Once that's done, you'll have a too-perfect image. Now simply knock back the opacity of the fixed layer a bit to reduce the "strength" of the fixes, bring the original skin stuff back in.

This means you don't have an overly perfection complexion, it's just better than what it was, and you can easily determine by eye the right level by playing with the opacity of the fixed layer.