Anyway enough of that here's the step by step for the box. BTW the papers used are from a pretty old Branda Walton, K&Copad, Dolls House and trimmed down to 6*6.
Again remember your pattern match.
Step 1 fold the paper in half lengthways as you would to make a regular card, open out turn and repeat so you have a nice cross fold line.
Step 3 You have a choice now of easy or tricky. Easy is folding the paper diagonally bottom left to top right corner and unfolding. I've shown the trickier version, fold diagonally but only crease from the bottom to the mid point before unfolding.
The box is finished now bar any decoration you want to add.