OK, so I know this isn't immediately the most exciting thing to do on a Sunday but combined with making your own bias binding this is one of the most useful sewing techniques you'll learn. Once you can make and sew bias binding you can make so many gorgeous things, especially when it comes to accessories and clothing.
On with the lesson......
Your bias binding is now folded into three parts....
Place the bias binding against the edge of the fabric you are trimming. Start with the wrong side of the fabric first as this won't be as neat.
Sew down the fold channel with a straight, medium sized stitch.
Then turn your fabric over (with the bias binding now attached along the edge) and wrap the bias binding over the edge of the fabric.
Then top stitch all the way along the bias binding. You'll want to do this slowly to start, folding the binding as you go. Again and medium sized stitch is good and just make sure it covers the first line of stitching.