Originally Posted by mamatobugboo

i've never done it, but i would imagine it would be better to cut your wavy border strips before you sew them on...that way if a mistake is made, you can just recut a border instead of having to fix everything.

I have a border book - it says to sketch your wave on some paper (to scale) to determine where you want the high curves and low curves. This actually applies if you are making applique wavy border pieces on a your border background. I think the same technique could be used to do a wavy border and just mark your strips with the templates and cut.

1.Cut your border strips, and make a plastic template from the paper drawing, adding 1/4 " seam allowance to the long flat edge only and identify the center of the shape.
2.On the right side of the fabric border strip, mark 1/4" in from each end and the center. This allows for seam allowance and identifies where you will be and end the design.
3.Place the template on one end of the border at the 1/4" mark, tracing the curve andmarking the beginning and center of each repeat shape in the seam allowance. These markings will help make any adjustments at the center area, by lengthening or shorting the center curve. Work from both ends to the center.

From there it says to applique, but for your purpose, you could just cut out the shape you have marked on the fabric.

Hope this helps!

and for copyright police, I got this info from Borders, Bindings, Edgings: the art of finishing your quilt by Sally Collins :D