One of my gals in my demonstrator group, Sofi Daniels, from Burlington, showed other demonstrators at a get-together this cool card.   She used Stampin' UP's wide grosgrain ribbon (5/8 inch).  It comes in 8 different solid colours and 6 different striped colours.  View it in the Idea Book and Catalogue on page 186.

You could use any size or number of ribbons, just adjust your cardstock square to match. 

Tutorial

(Click on any of the images to make them bigger.)

1. Start with a square of cardstock (in this sample it is 2×2 inches) and tape down the edges of the ribbon on the back of the cardstock.
2.   Then flip the cardstock over.
3. Start laying the ribbon strips down and weaving them back and forth.
4. Then finish off the back by using  glue dots to hold the ribbon in place.

Here's the card finished in a different colour.  Gorgeous!