I bought a rigid box (similar lunch box) with handle and opening clip.

Dimension:
- BASE : 25.4 CM
- HEIGHT : 19.7 CM
- DEPTH : 10 CM

I made some paper-models on the inside of the purse.
I got the gray fabric (plaid) and I cut following paper-models (remember to add about 2 cm at the edges).

I added a pocket inside the dimensions are 3 CM X 1.5 CM (1.5 cm folded 'cause I insert the elastic in the upper border of the pocket)

I made two triangles to sticking to the sides of my lining grey fabric that proves the opening of 7 cm (in the middle).

The measures of my triangle is
BASE: 13 CM
CENTER: 7 CM
up to zero (LIKE A PIZZA'S SLICE)

I sewed my triangles and I glued with fabric glue the inside fabric (LEAVE ABOUT 1.5 CM ON THE HIGH SIDES - NO GLUE)

I made other paper-models for the exterior of the handbag and following these I cut, first a thin foam rubber and then my outer fabric (leaving 2 cm from the edges).

ALL SIDES

I stitched along the folds of the bag on the 2 cm border that I left previously of all sides.

On the curves of the handbag remember to bend the longer side under the shorter; And sewn above the folded rectangles to hide the joints.

I sewed the pieces of leather around the handle and around the opening clips.

And this is the result
<-----

SHOULDER
I cut 2 strips about 3 CM X 126 CM
I folded inward 1 cm each side and I sewed all.
I added a small leather buckle and I secured it to the bag with a little square leather sewed.

NOW
GLUE ALL on the rigid handbag!

..be careful..

All the edges will "disappear" under the internal fabric (see pt.3)

Finally I added a ribbon / cockade that I made with this instruction (http://www.cutoutandkeep.net/projects/rosette_ribbon_brooches)

FINISH!

LOOK AD MY SHOP