Advent calendars, not the chocolate ones but those fabby old fashioned German ones with glitter. One each.
Be Icelandic on Christmas Eve, new pyjamas, books, carols on the CD player.
Wraps up their presents in boxes. Unwrapping and boxes are far far far more fun than the actual presents. Depending on size, the boxes can be space rockets. Stables, train sheds, caves for monsters, Noah’s Ark,
Making calendars. Hand prints or whatever, with those tiny calendars you can get from any reasonable stationery/ post office.
Learning a poem or verse,
Learning a carol. I hate Away in a Manger but one verse isn’t too hard to learn
Reading The Night Before Christmas
WatchingThe Snowman, ok they’re too young but so what
Putting out the mince pie and sherry for Father Christmas and the carrot for the reindeer. Don’t be all grown up and wash them up after he’s had them, there need to be crumbs and tooth marks as evidence.
Reindeer headbands, all reindeer need at least two walks a day and to run pulling a pretend sled...or a real sled on which they can be pulled along when tired...