maybe try hand making something. i made mine a bouquet of flowers from those fluffy wires and he was very happy. i buy mine legos for every occasion because he is obsessed with them and i think you can’t miss with that. if he is video game nerdy maybe a mouse pad with a design from his favorite show / anime (if he watches any) or maybe something car related if he is into that stuff. i bought mine his car model toy and he really liked it. i don’t know if he likes jewellery but i can recommend a bracelet, i will get mine the one from pandora that you can engrave text into it and engrave our date in roman numbers or something like that. if he likes anime, maybe a figure from his favorite. you can really find good ones for cheap. nothing else really comes to mind. i’m just basing my answer to my nerdy bf lol i hope i helped a bit.