Here is the other site I used and I thought I would share some tips with you to make this easier for you to make your own.
1. when you measure for your strap width do from the middle of your bust to the middle of your under arm.
2. make sure your fabric stretches equally both ways mine is a bit more of a one way stretch and it works but not as good.
3. if it is as cold there as it is here still get your self some band aids or take the foamies out of your strapless bra like I did lol
4. Make sure your fabric is extra wide or you will wind up with a top not a dress lol.
5. Have fun this is a blast