Image is from www.freeapplique.com
Appliqué is a great technique for bringing depth or texture to a project, or for covering up holes or stains on fabrics. It is best to start with simple shapes; you can always practice on scraps of material to get used to sewing around the shape before doing it for real.
Sites such as About.com and E-how have information about the different appliqué techniques and links to sites you can visit for further information. You can choose from lots of free appliqué patterns on http://www.freeapplique.com/. My personal favourites are the birds (as pictured above).