How do I clamp a beveled glue-up?

I have 16 pieces of ¾×2½×20" stock with a 22.5° bevel on one edge. I want to assemble them in pairs to form the legs for two octagonal tables. I need to glue the two beveled edges together, but have a hard time applying firm pressure on the joint to force the slightly wavy outer edges of the bevels to match.
—Tom Dwyer Jr., Niles, Ohio

A roll of reinforced shipping tape will solve your angled glue-up problems, Tom, but your likelihood for success will increase if you use stock that's machined and beveled as straight as possible to do away with those "slightly wavy outer edges."

Butt the points of the bevels together along their entire length. To prevent one of the pieces from popping up and over the other piece, attach clamps A over the joint with light pressure. If your clamp's pads don't span the combined bevels, add scraps between the clamp pads and the workpieces. Then attach clamps  B  using just enough pressure to bring the edges together along their full lengths.

Now, stretch pieces of reinforced shipping tape across both faces, as shown above left. Space them about 4" apart, and leave 8" extra tape beyond the edge of the wood. Remove the clamps and turn the assembly upside down. Apply glue to the bevel, and pull the beveled edges tightly together in a 45° angle using the extra 8" of tape as a clamp, as shown above right. After the glue dries overnight, remove the tape carefully to avoid pulling loose any wood fibers.