These cookies look fancy, but are really quite easy to make.
Outline heart shapes with black royal icing. (It's sometimes difficult to achieve a truly black icing. I use Americolor gel paste in Super Black for great color results without the funky taste.)
While the outline is drying a bit, prepare thinned red and black royal icing to flood the hearts. You'll want to have both colors loaded in squeeze bottles before you start. (Again, a true red is hard to achieve and I recommend Americolor gel paste in Super Red.)
Working three or four cookies at a time, flood the hearts completely with the red icing. While the red is still wet, place some black dots around the perimeter of the heart.
While the red and the black dots are still wet, gently drag a toothpick through the black dots around the edge of the cookie. This dragging motion is what creates that pretty design.
Of course, these would look great with other color combinations, too. I liked the red and black so much I did the whole Valentine's table to match. With young boys in the house, I opted for the plastic table cloth and the paper plates. That made the evening "special" without worrying about breaking anything - or having to do dishes!
You might also like my post about trying Martha Stewart's recipe for shortbread cookies with white chocolate icing. Those cookies look like conversation hearts. Sweet!