Last year, I visited the Stich Lab in Austin and purchased a pattern for a messenger bag.
The pattern comes with a medium size and a large size pattern.
I used some gingerbread fabric that my sister gave me, along with a candy cane and also  a polka dot remnant.

I wanted to make the purse a bit firmer, so I used interfacing and canvas.

I pieced the flap in order to add some festivity and color.

Polka Dot lining

I think I will use canvas for the next messenger bag I make.
I had seen some pretty canvas at Hobby Lobby.