This is actually a tip I learned from my husband years ago when we married. He wears bib overalls almost daily, and the straps tend to tangle. But, if you unbutton the front pockets, take the strap buckles and place them between the button and pocket and then rebutton it (or snap on some pairs) they will stay that way during the wash cycle. (if you simply buckle them as you do when you wear them, they come loose in the wash and tangle up)
Another trick I use is saving the buckles when he wears out a pair. Every so often the buckles break, and I have a spare buckle I can then use.
The rest of the worn out bibs make great potholders, or skirts for little girls or tote bags. There are lots of ideas on them if you google.
I place the two buckle straps in the chest pocket. Snap the pocket closed. Fold the bib forward in half and button both sides of the bib to the bibs green unused button holes at the bottom of the bib.