If it's short I tuck it into the metal loop on the hook.
If it's long and holding down my POS kayak or Stanley gear box, I roll it up, put it under the loaded strap and tug it under, so the strap holds it in place. It might work loose, so.....
If I have my Ducati in the trucks bed, I roll up the extra strap and electrical tape it to the load strap. Won't go anywhere then. A loose strap fluttering in the wind will eat Italian paint.