Personally i am good with stuff, but maybe some ideas off the top of my head.

• something merino (underpants, T-shirt, socks, buff, leggings, long sleeve)
• travel guide book, cycle touring / other adventure book, or for example i got gifted an extensive book about alpine roads and passes, it’s mostly aimed at motorists but still pretty cool to read around
• a small tool you maybe don’t have like a spokey, i always bring one
• small notebooks like the moleskine a6 cahiers
• voucher for something along a planned route, like a night in a hotel or spa visit