Here are some gifts that we have given our kids over the years.
dirt pile (yes we actually had a load of dirt delivered), with real hand tools, bug collecting containers, bug nets, rock picks, and a plastic organizer box to store their treasures in
pile of wood, box of nails, kids sized safety glasses, and some real starter tools (If you ask Lowes and Home Depot if they have scraps, they will usually give it to the kids for free.)
PVC, various PVC connectors (non threaded) and a PVC cutting tool (supervise this) - We went with 1/2” PVC.
pile of cardboard - including lots of big boxes (think appliance size), tape and round tip steak knife for cutting the cardboard
invention box - ask family and friends to save any interesting do dad to see how the kids repurpose it (I wrote a blog post about what types of random odds and ends to save.)
a box of supplies to work through challenges at kids who think.
supplies to go with the Ultimate Book of Kid Concoctions.
a homemade kit of supplies for Junk Box Wars.
another year it was Make Electronics and supplies for it
we've given a box of computer parts in which my son built his own computer
some years it's been lots of hands on science projects - scored on clearance or sales
it's been general making supplies, I wrote a blog post sharing what my boys use the most
this year's surprise is - Ha, my kids read my blog so you’ll have to wait to find out.
You could also give items to take apart, a mini screwdriver set, and a book such as Teardowns: learn how electronics work by taking them apart by Bryan Bergeron.
My son is an excellent shopper and has written a blog post sharing tips for finding inexpensive making supplies. He’s really changed how I look at things when I go shopping.