Question for he lady ravers

My dad, stepmom, and I go to raves regularly and it being the holiday season and we are going to Tulum in January; I want to get something for my stepmom that is suitable and functional for the scene.

I am specifically curious about what neat contraption or whatever you use for your phone that you have and can't go to events without? something that keeps it safe but easy access is something I think she would love.

I would also love to hear other ideas not specifically related to keeping the phone safe but whatever else it is you have that you like so much and bring with you to every event.