Miter long thin pieces

[scifisawguy]

I'm making a scrollsaw clock. The front, back and sides are 12" in length and 1/4" thick. What's the best way to miter these together? Is there a jig I can use? Router or sander? Thanks for any help?

[vz4bpd]

I have had excellent success with a picture frame mitering tool. The unit is available in any woodworking catalog. Is has very sharp blades that will shave the wood perfectly.