I did this because the straps were too long. Although it doesn't fall down as nearly as much, it still does. Oh well.
If you have a top that has straps that fall, this is for you!
I tied two bits of ribbon together onto the front strap. I tied it up a few times and then cut the ends off of the last knot.
For the ends, I tied a few knots and I cut the loose ends after. Then melted the fabric a bit with a lighter so it wouldn't come out easily.
Tip: to get the original strap to be thicker than the ribbon, make sure you're tying the ribbon around the strap not making the ribbon one? I don't think that makes sense but I don't know how to describe it xD .. See how I'm holding the strap in the photo?
Well basically, just do whatever you feel is good :)