This is SO easy! The box is simply a 6 x 11 piece that is scored at 1 inch on all sides. Then score at 5 and 6. Cut to fold lines on the long sides and assemble. The flowers are from the birds and bloom sizzlets and just pulled around my finger to get them to stand out.
This is also the faux denim technique, from Technique Junkies. Just requires sliding your ink pads across the paper. Check my gallery for the 6x6 technique page with directions.