Try as you might, you may never get that glowing skin that you so badly desire. It's OK, you can fake it.
You can, of course, buy facial highlighter, but you likely have one in your makeup bag, ready to pull double duty. I have come to depend on shimmery white or nude beige powder eyeshadow to give me the fresh face that is easy and completely natural (looking).
Look for a shimmer without sparkle in either pure white or a pale beige. Fair skin will pop best with a snowy white, while deeper skin tones look best with beige hues with the tiniest bit of gold or bronze. Steer clear of anything that has a silvery cast or visible bits of glitter. Your objective is to highlight, not hi-beam.
Apply the color with your ring finger to the bone just under your eye, above where you apply your blush. Start beneath the outside corners of your eye and blend no further than your pupil toward the bridge of the nose. I also like to apply a bit to the bridge of the nose and the inside corners of my eyes.
The idea is to catch the light as you move, not to look shimmery, so you may not even be able to see the color as you look straight into the mirror. Move around a bit and see what impact it makes. If it looks like you have eyeshadow on your face, blend a bit or try a different shade, both lighter and darker, to see which looks best on you. Most of all, have fun!