My parents give my son huge elaborate 1000 plus pieces lego kits. They are great for school holidays. We have a meter tall hulk buster iron man guy that took 4 days of piece and quiet.

iTunes card

A science kit
Lego technic
Books

His favourite sporting teams shirt/ jersey
Basketball hoop
Scooter
Handballs
Cap
Fishing gear
Bluetooth speaker
Backpack
Movie vouchers
Sunnies

Depends on what he does. My 13yr old nephew is into his playstation so I usually just get him a PS gift card or a new controller etc and he loves that because parents won't spend too much on it (rightfully so) but I'm the Aunt so who cares haha

Scooter

A leatherman? A tool set?

lego
vouchers
books
a nice cap
headphones
bluetooth speakers
watch
sunglasses
water bottle with fav logo
camera

Money

Lego

Fitbit

https://www.stayathomemum.com.au/shopping/gifts-shopping/christmas-gift-guide-stay-at-home-mum/

I have a 12 Yr old son and I'm struggling too!! The stuff he wants I won't buy (TV for his room etc) he already has a phone, xbox etc. If he's a gamer I'd buy xbox or PlayStation vouchers. I found a cool slogan TShirt on redbubble that had the Nike tick with a sloth lying on that said just do it.... Later. Thought that was appropriate haha. If he's sporty, a new rugby, soccer or basketball etc. Into YouTube? Get him some merch from his favourite YouTuber. A Phone case and pop socket.