I have had my "Blue Ribbon Quilt" posted in "Pictures" under Tumbling Blocks for about 5 years now. I used different fabrics for each cube so used a lot of scraps.
The site Gay listed is a good one for directions. I did mine just l little differently. I sewed the two side triangles together, then added the strips around the outside. The top triangles I left separate and added the outside strips to each. Then I sewed one top to each side (in the correct order) and left them that way until I had lots of these halves made. Then the halves were put together into strips to complete each cube. All straight seams.