I was looking through AliExpress and found a neat project to do with my kids. The three dimensional LED Christmas tree (https://www.aliexpress.com/item/Three-Dimensional-3D-Christmas-Tree-LED-DIY-Kit-Red-Green-Blue-LED-Flash-Circuit-Kit-Electronic/32584816522.html). If the link doesn’t work then go to aliexpress.com and search for “3d christmas tree led kit”. It’s a full kit including all of the parts to make a blinking tree with either batteries or USB power.
I ordered a couple dozen kits and have been assembling them at nights and over weekends to give as gifts. It helps a bit that my kids already knew how to solder but it’s still fun assembling them together.
You will need to have a soldering iron, solder, a side cutter (wire cutter), a really small phillips head screwdriver, and some patience. I found a youtube video of someone assembling the same kit (https://www.youtube.com/watch?v=ruoIYrrV9_w) You will definitely want to skip back and forth because it took him 90 minutes to assemble. That’s what you should expect for your first try. He and I were using a soldering iron that’s a bit past what you’ll have sitting around the house.
One fun thing to do (yes, fun – I’m a bit nerdy) is substitute the LED colors on the tree. I had previously purchased a set of different colors of LED’s (https://www.aliexpress.com/item/500Pcs-lot-3MM-LED-Diode-Kit-Mixed-Color-Red-Green-Yellow-Blue-White/32749396579.html) and replaced colors to make the tree using red, white, and blue as well as red, yellow, and white. The voltage requirements for some of the colors are higher than the supplied LED’s so they will be a little bit dimmer but still look good.
Even if your attempt explodes, you’re out less than $5. As I said, I bought plenty of extras because we were all a bit rusty on our soldering and assembly skills.