This is a very handy idea thanks Valita, go to her blog link below some pic's of how I did this one below
Cut a A4 card at 11 inches
These are the score lines 2 1/2inches, 4inches,7inches,8 1/2inches, card placed landscape
Score lines card placed Portrait are at 1 1/2
These are the cut lines cut along the 1 1/2 score lines until 2nd score line
Mark at half way point 5 1/2inches both sides and score from this point to next score point at the 1 1/2 line creating a triangle of score lines
Then cut down first score line
Be careful not to cut this tab off
Crease all fold mark well
Apply strong tape or glue to tabs
These will tuck under large flaps to form box base
That's the basic card made
Now its up to you here is what I did