This is the first of two different kinds of corners.
Push in the sides and smooth them down to the bottom, making a clean crease. Fold along the edge of the paper to make a triangle point. Repeat on the top (or flip the box over so that you have your flat surface to help you). Make sure that you have a clean crease along the edge of your box and then fold the triangular tabs in towards each other and tape in the middle. Or tape each tab separately if they don't meet in the middle.
And don't worry, gift wrapping, just like anything else, takes some practice!
This How-To uses our Chevron Waves Kraft Wrapping Paper in Silver.