I like cutting tenons on the band saw because it's quick, easy, and accurate — especially with this fence and stop block. As you can see in the drawing, the plywood fence is attached to a base that can be adjusted and clamped to the table. A cleat registers the base square to the table.
I made the fence and stop block 3″ tall. That's tall enough to handle most tenons, but low enough to keep the blade guides close to the work. To cut the slot for the stop block, drill a pair of 3/8″-diameter holes in the fence and remove the waste in between with a jig saw. Then, drill a hole at the same height in the stop block for the bolt. The 6″-wide base is the same length as the fence.
At this point, you're ready to assemble the fence. Begin by attaching the cleat to the front edge of the base. Then, attach the fence to the side of the base with countersunk screws. A carriage bolt through the slot with a star knob makes adjustments quick and easy.
Pictures are available from the Titled Link above.