Wooden dowels of about 1/4" in diameter make great anchors for elastic bands used to strap the wings in place.
On occasion, it can be found that the location of the dowel to achieve a good CG would place it straight through the fuel bottle or some other central component. A solution to this is to use wire on the underside of the plane.
This picture illustrates coat hanger wire bent appropriately:
Here is an example of the wire being used to hold down the elastic bands to hold the plane to the wing: