I always write a card for every kid. I used to include a USB stick with all of their performances from high school (audio and video), but recently have begun just giving QR codes that link to a limited-time Google Drive folder.

Last year, we purchased a laser engraver for our program. (Catching up on 20 years of UIL plaques meant it was more economical than paying someone else to do it). I bought some metal business cards and put the QR code on one side, then put their name and major accomplishments in band on the other side. That was included in the card.