Quick craft idea for young teens

[SnugglyJumpersMakeItBetter]

Help me help me help me! I need a craft activity that's not too 'lame' (or whatever the youth of today would say!) for a 14 year old boy and 12 year old girl. Something that can be quick and easy but doesn't have to be if they'd like to spend a little longer on it - last year painting rocks was a big hit! I'd like it to be something they can keep if they want to without being teased if friends see it in their room. Everything I've seen is either too complex (build a scalextric WWII Spitfire type thing) or insultingly 'little kiddy' (paint a plastic rainbow suncatcher sort of deal). I'm desperate for ideas!!!

How about making cards? You can get blank ones and bits to decorate. They could be made with specific people’s birthdays in mind.

Air dry clay - can get cheap turntables and a set of clay tools and they can make something nice they can keep. Could do v simple things like Xmas ornaments or do coil building to make pots.

I'll caveat that I don't have children, so might be WAY off.
Crackers? Either as a Christmas theme or for someones birthday/fathers' day? You can buy kits, or make the components from toilet rolls/paper/the cracker component.

Edible veg? Large plastic pot with soil. They can tie the bamboo poles to make a teepee and grow mange tout or french beans.

If we count edible gifts as crafting it opens up lots of options. Jam or lemon curd making, fudge, truffles etc

Diamond painting?