Every year I go to a conference in New York, and wheeling my suitcase with a briefcase (holding my computer) on the handle. And every few minutes the briefcase slides off. It drives me nuts, but I've never figured out a solution.
Recently I got an email from Demi Hugger, showing me their product. It seemed like a problem solver. They sent me one to try, and I have to say it worked. I took it on a trip recently where I didn't have my briefcase, but rather my trusty backpack, pictured below.
How it works:
The Demi Hugger is like a big sash with velcro. The velcro strip can attach anywhere on the long neoprene strap. It can be wrapped horizontally or vertically. There's an opening so the Demi Hugger fits over the handle/pull, attaching it securely to the luggage. Actually, there's an opening each way to fit it on the handle. It weighs very little but feels quite strong.
While I'd use for smaller items like my briefcase or backpack, you can also use it for instruments and sports equipment - things that are oddly sized.
They sell for $32 plus shipping on Amazon (affiliate link).