Besides assorted craft materials and PC my desk has a dual purpose crocheted rubber duck: it serves as a pin cushion and my debugging friend! I made him and he has lived there since my first year of university.
I also keep a mug from my university, scented candles, notepad and pen (for all my tech savvy-ness, quick notes are still better handwritten) and whatever crafty project I'm working on.

My desk is honestly a mess (I have to clear it ~three times a week to have any space to work on) but they say creative people have messy workstations so I take my inability to keep an orderly environment as an expression of my creativity.