That was a nice idea to present a gift related to his/her interest. Actually there are some products specially for crypto lovers.

Few gift ideas :
Ledger wallet
Physical Bitcoin - may be available in etsy
Bitcoin pillow
Coffee mugs, t-shirts and caps with bitcoin quotes.
Crypto Books
cryptocurrency voucher
CryptoSteel capsule
price ticker -shows the price of the coins

Hope the above list useful to you.