I go with the very low tech!!! I took a piece of scrap cedar about 1x2x10. Wrapped a piece of coarse sandpaper around a dowel and rubbed a rounded grove, lengthwise, in the wooden block. I place a piece of sandpaper around and block and int the groove. Rubbing the long sandpaper block along the sheer or chines gives a nice fair and rounded curve.

Of course, you can make different radii by using different dowel sizes. I've also made the sanding blocks out of styrofoam insulation.

Sorry no pictures available right now.

Cheers,

Sean