2 major factors in taking good card pictures that I've found is Lighting and background. Most built in cameras on cell phones these days are sufficient as long as you have good lighting and background. For cards, I have a point and shoot facing down toward a stand that has a blank 8.5 x 11" piece of paper. I center the card on the paper, zoom to fit field of view, center the camera, and use a 2sec timer on camera (so camera doesn't move simply by pressing the button). I illuminate the area with a dimmable LED light (no flash!), try this:
https://www.amazon.com/Dimmable-Digi...s=neewer+light
V'oila. Quick example with no touchup is attached. Hope this helps.