(these are examples of "good" foundation)
The most aging thing a woman can do is wear too much foundation that looks flat and lifeless on the skin. If you check out the hottest women on the red carpet, they may have a tremendously dark smoky eye, or even red red lips, but always fresh dewy skin that looks as if it's lit from within. As someone who grew up with oily skin, I didn't always embrace the sheen, but now my opinion is that I want to see something that falls just (slightly) short of a face that looks highlighted with vaseline. If you browse through Victoria's Secret catalog, you'll see that all the models look just a little, well, sweaty. Like they've been up to something, maybe?
The key is to not coat your entire face in shimmer-just to pop out the areas you want to accentuate; the browbones, the inner corner of the eye, the tops of the cheekbones...sometimes the bridge of the nose and the chin, depending on bone structure.
I usually ask my brides to just carry blotting papers on their wedding day if they are prone to an overy greasy forehead or nose;piling on powder can create a cakey look.
Try some shimmery powders or creams for highlighting-but make sure they're pretty high quality-lower end brands tend to have a more glittery look, not the sophisticated, highbeam effect you're looking for.
Also look into using a tinted moisturizer instead of a foundation-it will even you out and tone down discoloration without the heavy look you can sometimes get with foundation. If you just feel too "nekkid" in tinted you can either spot conceal problem areas on top of the moisturizer, or mix a little foundation in with the tinted-gives you a bit more coverage but still the moist glow. Another thing you can do is sheer out your favorite foundation by using a damp sponge.
Foundation is not supposed to oblierate every pore or cover every flaw-if you see areas that still need a little help after applying your base, feather on a fairly dry consistency concealer. that way you're not wearing a full mask over your whole face, you're just concentrating on "problem" areas, such as blemishes, scars, redness, or broken capillaries.