In preparation for the next Mothers Class, I found a way to get two accordion fold cards from one sheet of 8 1/2 x 11 cardstock.
The short piece (on front) measures 3" high on the left, and the tall piece (back) measures 5 1/2" high on the right, for a total of 8 1/2", which is the width of a cardstock sheet. By cutting diagonally across from 3" on one side to 5 1/2" on the other, you will have two pieces exactly the same size and shape.
Next, from the thicker side, score at 4" and 8" for the folds. The Scor-Pal makes it easy, but you can use whatever works for you.
For the designer paper, the same measurements apply, giving you two pieces the same size and shape as your cardstock pieces. Simply cut and trim the pieces to fit each panel, leaving the desired amount of border.
The middle panel on the back (not shown here) will show when the card is folded, so you will need to decide how or if you want to decorate it. On this card, I had enough dsp to cut a matching piece. On the Fancy Folds Card posted earlier (scroll down to take a look) I used a coordinating piece of striped dsp.
Now that you have some measurements and simplified instructions, I hope you'll give it a try!