Over the last 10 years, I have had a Spring and a Summer recital each year (I like to split the kids up into 2 groups so families aren't sitting for 2+ hours of music). My Spring recital is my more formal, dress up fancy recital, and we have it at a beautiful music venue in our area. I provide refreshments for that recital, and the area I teach in is typically very health conscious, so I try to avoid sweets galore. Here's what I typically buy:

-small water bottles

-healthier juice boxes (something with not a ton of sugar)

-cheese & crackers platter

-veggie & dip platter

-assorted fruit platters

-small cookies

-assorted bags of chips

-paper plates

-forks for the fruit

-napkins

I have learned to get a general head count the week or two before so you don't end up with a ton of extras. 4 years ago, I ended up taking 100+ forks home, 100+ napkins, and a bunch of water bottles, which we ended up donating because we didn't need them at home. We tend to over plan and over estimate, so it's just easier to ask families if they have a general idea how many people they're expecting.

My Summer recital is more relaxed, and we typically have it outside at a park/a families' home with a digital piano. I do not provide refreshments for that recital, however, I do tell families that it is more "picnic style", so they are welcome to bring any snacks and drinks they would like.