How do I cut tenons in long stock?

I typically make tenons using a dado set on my tablesaw, but for a bed rail I'm making, that process seems unwieldy and unsafe. Is there a handheld method to make tenons in large stock?
—Henry Scales, Chattanooga, Tenn.

Easily done with a router, Henry. Chuck a short pattern bit into your router. Shown right, these bearing-guided bits are sometimes sold as dado clean-out bits. Glue and screw together a simple scrapwood T-square like the one shown below.

To begin the process, mark out your tenons. Then, clamp your rails as shown below to begin the tenon with the edge cheek. Set the bit to rout away the depth of the shoulder, then use the T-square as a bearing guide to rout a first pass, removing about ½" of the bed-rail material. Reposition the square closer to the mark and repeat the routing, removing more material. For the last pass, align the T-square with the marked tenon and finish the cheek.

Repeat the process on the opposite edge cheek before laying the rails flat to rout the face cheeks in the same manner.