Hi,
Hate to butt in
I make the bows and yes, we have beentold to put two bands that way if one breaks the second can be used and your not out your $$.
As far as getting them straight I myself still have issues. Have you tried Puppy Flowers?? You don't need to worry about them being straight.
Here's some you can see...
http://www.puppywraps.com/gpage3.html