At my cousins wedding, for her mehndi she gave all the girls pink churiya (the mehndi theme was pink and orange) to wear whilst there and to take home with them. I thought it was such a good idea and it went down a treat. On her Walima they gave out those mini boxes of celebration chocolates which were wrapped, and had a tag on with a little note from the bride and groom saying thank you and a dua at the bottom. It was a fab idea.
Churiyan are nice! If anyone does this though, i hope they make sure htey get diferent sizes, esp if theres alot of young girls. you dont want to make them feel excluded or left out for no reason..