Mine are teenagers and we do The Box on 1st December now , but for little DC , I think it would be too far ahead and they'll be frazzled by the 24th.
We used to rake them out for a walk after lunch, just as it was starting to turn dark(ish) , feed the ducks or the reindeer. When they were outside with DH , I'd "Oh, I'll just check the back door is locked" and put the boxes in front of the fire for when they got home (They never twigged or if they did , they never said)
CEB were to get them calmed down and ready to sleep.
They do them now on the 1st , to get more use from things .(All things they will use anyway)
PJs- (DD has a set from Victoria Secret Pink for winter and a Primark or Sainsbury set for Christmas Eve. She wears these all winter /spring . DS gets Primark or Sainsbury and a robe)
Jar of sweets
Bath smell (Lush bathbomb )
Nice pens (to use at school after)
New underwear
Chocolate
New mug and a sachet of drinking chocolate
Book
DD insists on her Winter bedding going on for Hallowe'en night then here Christmas fleece on Dec1st.
DD has Primark flannel woodland animals and tiny fir trees (not Christmas) and DS has red with snowflakes .
YY to Matalan
Costco
Home Sense/TKMaxx (they do really lovely boxes that I use to store Christmas decorations in after )
I start looking in late Sept then the shops start seriously stocking things after Hallowe'en.