The tricksy knitter is a funny creature; she probably loves pretty shiny things. But she is probably a bit of a tomboy too. I've been experimenting with adding ribbon to my knitting, and I think it might strike a happy balance between girly and tomboy.
Simple Embroidery with Ribbon
Ribbon Eyelet Row
Another way to include ribbon in your knitting is to use eyelets. An eyelet is usually made by knitting 2 stitches together, then bringing the yarn over the needle. (Otherwise known as k2tog,yo). For more an making a row of eyelets, see Eyelet Gathered Ruffles.