I'm going to use a magnetic snap on my next Bow Tucks. I have never used one before so at which stage of putting this together do I put the snap in? I was also thinking of putting a small flap on the purse where the tie for the button would go and put the snap on that. I think it still needs a little something there. I just don't know how to make one of those. Can anyone tell me how to make one of those?