Lurking for ideas, I have a DS (17 next month) and a DD (14.6)
When they were little we did the CEH (Christmas Eve Hamper) to settle them and mark the start of "off to sleep now" and the Stockings to keep them occupied at 5am. 
Now their presents are ££ and tiny, they have a small but expensive pile of presents. I'm doing a Dec 1st Hamper so they can use the presents throughout December. It's things they'd need anyway:
Haynes teenager manual (but I'm going to look at the Ladybird ones too0
Sweary colouring in book + nice pens (that will be used in homework)
Some of that Below the Belt for DS if he doesn't stop trying to thwart my Christmas Plans the little toad ..........
Bulldog wash/scrub/mask
Jar of sweets (big Kilner jar which I either pinch for the kitchen or they keep for pens/hair things/cotton wool)
Both have PJs (winter ones) that they can start wearing on the 1st
Fluffy socks for DD
Robe for DD
Nail varnish (DD) little bottles
Chocolate Advent Calender - nobody is too old for a calander
Mug
Named Nutella for DD (I sent off last week so I'm hoping it'll be here for the 1st, if not she can wait till Christmas)