Talk to the parents association. They may be planning a group thing. My daughter competes as well and every year one of the other moms collects whatever you can give (seriously, anything from $0.50 - $50.00) and with the collected money, puts together gift baskets for each coach. We have 7 coaches and this mom is fabulous at finding deals. The baskets always contain some sort of gift card and some other stuff, usually around a theme. (I think this year it will be a lot of travel stuff since we're going to a meet in Fl in January - our first out of state - way out of state) Then ALL the girls sign a card, regardless of what they may or may not have contributed. Everything is presented to the coaches at the holiday party.
If they aren't doing a group gift, then find out if there's anything you can do for the coaches. Do any of them have small children? Are you willing to watch those kids during a meet at a time when your daughter isn't competing? Can you offer - or organize and offer- to mop all the mats and clean the gym one weekend? Is there a special skill you have - do you knit? is it cold where you live? can you knit a scarf in the team colors? You could even make scarves from fleece in team colors with little to no sewing.
How about a 'meet survival kit' - get them a little pouch with some hand sanitizer, lotion, chapstick, a couple of band aids, travel tylenol, some peppermints or gum, a small card (laminated) with the teams contact list, water bottle clip and a lanyard w/ a card holder on it so they can put their creditials in it. (not sure if it's a USAG thing or a VAUSAG thing, but our coaches have to have their creditials visible at all time). You could get everything for under $10 per coach.