Select four different paper (a great way to use up your scraps), and cut four large squares (punch them, die-cut or just use scissors!). If you have a corner rounder punch, round off opposite corners. If you don't then you can buy yourself one at Regal /Craft Cards or use a coin as a template and cut with scissors..
Cut out a square in another colour that is big enough to fit all four square with a bit of space between and around them, and stick the smaller squares in place, with the non-rounded corners in the corners of the backing square (see photo). Mount the whole thing onto a square singlefold card from Regal Craft Cards
You can just stop there if you like, but if you want to add further detail you can either add an embellishment to the middle of the shapes or to one or all of the smaller squares. In this example I've punched out two circles, added some holes and threaded some stranded embroidery cotton through. You could use a button as an alternative.
One of the great things about this card design is how versatile it is - you can vary the colours, or emboss each square with a different pattern or paint them etc, and couple this with embellishments appropriate to literally any occasion from weddings to birthday, to Christmas. A little tip though - unless you use a really "loud" embellishment, the paper is the star of this card, so don't skimp on quality.