I make my digital card spreads by using a photo of a tabletop, either a stock photo or one I've taken, then layer the card images on top of that, at angles. I also add a drop shadow to the card images. I've used Photoshop and/or Canva for my layouts.
Sometimes I also print the cards out, cut them, and take a photo of them on a flat surface. I use two copies of the card to do this so I can show the front and back at the same time.