This isn't a fancy as Tod's but it works.
I took a piece of 4/4 White Oak and made a sled to go into the miter slots on my TS. I fastened a piece of Baltic Birchcut a grove using my Dado stack for a 1/2" key in the face of it. Then 1/2" over I dadoed a slot in the face of the Sled. It makes short work of Box Joints. The first cut is made with the board against the keys, then you just keep making cuts indexing the last cut over the key. To make the apposing set of fingures just pplace one finger of the already dadoes board over the key and repeat as above.