I had let my daughter know about silicon bands that are sold at a number of places that act as 'sleeves' of sorts to hold the band on in case the connection comes loose. She hadn't thought about it, but was VERY happy she got some as their magic bands came loose more than once on their trip to
Disneyland a couple weeks ago.
Her husband's in particular kept opening up, and by the last day even the silicon band didn't help and he lost it. Fortunately it was their last day - she removed the band from their account to prevent unauthorized use and they finished their trip without it.
I will say she was surprised to hear from Disney that they had the band (either found by a castmember or turned in) and they were shipping it back to her.