I have only made one Bow Tucks purse so far and there are definitely a few things I would do differently.
First, I would quilt the material used for the top half of the bag first and then cut it to size. I would do the same for the bottom piece. Then I would sew them together. The FMQing has a tendency to "shrink" down a little and I found that my pieces were slightly smaller than what the pattern called for.
I made the handles a length that was comfortable for me. I don't think I even measured. I also used the cotton tubing that is normally used in making your own piping in upholstery projects.
I would also make my loop for the button closure a little smaller.
Oh, and I used blue jeans for the bottom piece.