Take more than one photo. I typically take at least 4-6 pictures of each project, sometimes as many as a dozen or more, especially if I'm trying to capture something shiny or glittery. It's all digital, so there's nothing to lose by taking extra photos. Try getting shots from different angles, and rotate either your project or your light souce so that the light falls in different ways. Over time, you'll find the set-up that works best for you in most cases. For example, I've learned that for morning shots my project is best placed facing a certain way, but for afternoon and evening shots the project looks best facing a different way. In addition, if it's either overcast outside or unusually bright and sunny, I'll need to make adjustments.
I personally prefer to photograph my cards from a slight angle, rather than face-on. My cards often have a lot of dimension and texture, and the angle helps to show that off best. That said, a word of caution: avoid photographing your card from such an angle that it becomes difficult to see the front. If your card is turned away from you more than 45 degrees, it's probably too much (my opinion, anyway.) Think in the 15-20 degree range. Or, in clock hands terms, the project is at the 12 and you're at the 6 - you want your project to face the 5 or 7. Does that make sense?
In the attached photos, you can see how much more visible the stamped image is when the card is not turned too much.
The wheelbarrow image and sentiment used for my sample card are from Annie LaPoint's Spread a Harvest of Hope by My Favorite Things.