I've been making cards for about 30 years and here's a few little tips I'd like to share that can help make your cards have a truly professional finish. It's really all about attention to detail.
1) If you make your own cards from scratch, like with this cupcake card, they can be folded by hand. However, you'll get a far better fold if you make use of a card creaser or scoring board where you emboss the folding line on your card first.
2) Disguise hand-cut card and paper, plus add extra dimension by applying a little stamping ink in a similar or slightly darker shade around the edges. Gently swipe a small craft ink pad across the edges of the paper. You can also achieve a similar effect by rubbing the side of a colored felt tip across the edge of the paper or even craft chalks.
3) If all your papers and card are smooth and flat then the finished design will probably fall flat too. Add texture to some of your handmade card. One way to achieve this is to emboss your card or paper. I often emboss the 'frosting' on this cupcake card design with the Sizzix Swirls embossing folder and add glitter glue to the raised swirls. You can also emboss designs by hand or purchase embossed paper and card.