Johnny, you have a good idea with practicing on some cheap wood. Pine is great and soft. Altho really its not hard at all to sand out a riser and finish it with rasp and sandpaper.
Pesonally i use a bandsaw and cut out the rough shape when the bow is glued together. From there i use a belt sander to grind it to shape. File work from there to sandpaper. After a few risers the process goes fast, but be careful as you can grind to much, go slow, inspect often and you'll get it.
Large companies use CNC when they are kicking out production models by the lots. but to get a 5 and 6 "D" CNC cutter is 50 to 150K, so most don't use them. You'd be very suprised how close you can get back to back risers with the use of a beltsander, band saw and some file work.
Dave