Card Stock:Pacific Point, Garden Green, Real Red, Whisper White
Ink: Pacific Point, Garden Green, Real Red, Pumpkin Pie, Daffodil Delight, Basic Black
Stamp Set: I Dig You
Ribbon: Retired Pacitic Point Striped Grosgrain
You start with the following sized squares of card stock.
8 x 8 inches - Color A (Real Red) 1 square
3 3/4 x 3 3/4 inches - Color B ( ) 2 squares
3 1/2 x 3 1/2 inches - Color C ( ) 2 squares
3 x 3 inches - Whisper White 3 squares
You will also need some coordinating ribbon.
Score the 8 inch square (Color A) at 4 inches along both two adjoining sides. The Simply Scored from Stampin Up is great for this - but I have found I do much better staying in the grooves if I stand up - not sure why but it works for me.
The lines intersect in the center making 4 smaller squares. Cut along one of the score lines from the outer edge to the center. Turn the piece of card stock so the cut is on the right hand side as shown in the photo above. Working with the lower right square fold diagonally from center to square tip. Put adhesive on the triangle that borders the score line cut and the outer edge. You only want to add the adhesive to the triangle - not the whole square - or it will not fold.
Fold that up behind the upper right square matching the corners. This will form the cube.
Here is the cube. The diagonally folded square is behind the square in the upper right.
The photo above shows the back side of the cube. You can see the scored line - the adhesive would be behind the triangle on the upper right corner.
Here is the folded card.
This shows the card half-folded. The square that is adhered to the diagonal is pulled forward and toward the card front, folding on the diagonal score line, until it lies flat.
To decorate my card, I used the new I Dig You stamp set. This is a fun set for boys. I used the Many Marvelous Markers to color in the sections of the stamps. Once all the sections have been colored, huff on the stamp before stamping on the card stock. The huffing is just making a short fast breath (or huff) onto the stamp. This moistens the ink if it has started to dry out.
I layered two of the images on Garden Green then Pacific Point. These two will be used on the front of the card and the square that is adhered to the diagonal. I don't layer the image on the bottom inside of the card because it makes the card stock drag over the extra thickness when folding. 
Add the ribbon. Cut plenty of ribbon so you can tie a bow at the card opening. Fold the ribbon in half and place the halfway mark at the fold of the card front. Attach the ribbon with some snail adhesive or double sided tape.
Adhere front image over the ribbon. 
Adhere the other matted image to the upper inside square - this is the square adhered to the diagonal fold. Adhere unmatted image to the lower inside square.
Here is the card opened up. 
To finish - tie the bow along the open edge of the card. 
This is another cube card. The club last weekend made these.
Card stock: Peach Parfait, Pear Pizzazz, Not Quite Navy, Whisper White
Ink: Peach Parfait, Pear Pizzazz, Not Quite Navy
Ribbon: Peach Parfait
Stamp Sets: Look Who's Turning, Bring on the Cake
And here it is opened. I did mat the lower inside image on a sheet of Not Quite Navy but it does make the card hard to close. The other card moves much more easily since I did not mat the image on an additional color of card stock.
Hope you try these - they really aren't hard and once you get the hand of the fold it comes easily.
And if you are struggling with it remember - it always goes better with CHOCOLATE!
