I've said this before: blush is an underrated beauty must-do. The right shade and the right application adds pretty like no other cosmetic. Sheer pink, peachy pink or coral works for most complexions; you can also take inspiration from the colour you flush when you rush a shoe sale.
Sweep blush along cheekbones for sophisticated beauty, or onto the apples of your cheeks for look-young radiance. In this video, pro artist Sue Devitt shows an interesting application that takes a sheer blush higher up than you'd think for a fresh effect, and intensifies the glow with a gel-to-powder formula on top. Note, however: stop short of the undereye area if hollows or wrinklies have taken up residence there. And when it comes to Sue's lip tip, you'll want liner that matches the gloss.
Update: Denise's comment below prompted a bit more of an explanation on my part; thought it would be more effective if I put it here. I think the keys to her application are the right brush and sheer powder, D. Most of the colour ends up on the apple; just a bit hits under the eye. The brush she uses is flatter than a typical blush brush, with softer ends, and she wields it differently from a regular fluffy brush as well -- it's flat against the skin.
Countless makeup artists have told me that women with more mature faces should avoid placing blush too high in order to avoid hitting textured undereye areas with colour. This would be what they meant.
And holy sheesh, does Sue not have the most gorgeous, healthy-looking hair? Distracting!