DD is a Boxing Day baby, so we have done mostly separate presents but sometimes it has been a joint one (the year she got an iPad, her birthday present was the case and she got both on 25th, for example).
For her first Christmas, I bought a small hardback copy of "Twas the Night Before Christmas" as the bedtime story for 24th, and that has been read every single Christmas Eve since (DD is now 13, and SHE asked for it last year, having well grown out of bedtime stories!) 
We do the Christmas Eve Hamper, coming out after dinner on 24th. DD lights the Christmas candle (as the youngest in the house) which is an Irish tradition to show that even if the Inn at Bethlehem was full, there is room in our Inn for weary travelers, and we have a few minutes to quietly remember the good and bad things of the year finishing, and to remember family no longer with us, before saying an "Our Father".
Then the box comes out, which has grown slightly over the years. But it holds DD's stocking, and a plastic plate and glass with Santa on them. The family copy of TTNBC. DD's fluffy snowman covered hot water bottle. (Most reused since the 1st year, the remainder over 10 years now). And some new things - PJs for all 3 of us, lush festive bath bombs for DD and I (and maybe a nice shower gel for DH if we find one he'd like), a Christmas beer for DH (he likes craft beers), hot chocolate for us all (the lump of chocolate on a wooden stirrer/spoon) and maybe some kind of nibbly snack to go with the beer.
DD puts out her stocking and a glass of milk, and puts a carrot (for the reindeer) and some cookies that she baked that afternoon on the plate. Then goes up for her bath, into fresh new jammies, back down for hot chocolate and up to bed where someone reads the book for her. So its' all about settling down the excitement to allow her to sleep.
I always include a book in her stocking, just like there was always a book in mine. In those early couple of years, there were board books and ones suitable for small hands, as well as a couple of classics for bedtime reading - a large collection of Beatrix Potter, the Wind in the Willows, the entire Narnia collection etc.
And some fruit and sweets, along with some fun bits and pieces, and at least 1 nice but useful thing (fancy knickers, colouring pencils, funny rubbers, hair bobbins, ...).
We have always had a present under the tree from DH and I for DD, as she gives presents to us, and we give to each other, so we didn't want her to notice and realize there was none from us to her - but that is usually something useful like clothes or sports equipment.
Baking cookies on 24th afternoon is a tradition for us. I always baked with her, even well before she turned 1 she could mix the wooden spoon through things, and pour in a bowl of ingredients with help. And roll out dough to cut with cutters herself (but it took a while before those versions were bakeable, and longer before they went to anyone other than DH or I).
But to make it work on 24th, I always do a "cut slices off a log of dough and bake" type recipe, not a rolling out and use cutters type. No decoration involved either. And I am sneaky - I will always make sure that we've made a batch in late November/early Dec and frozen half the log - so if time is not on our side on 24th, I can take that from the freezer, and it is sliceable within an hour with no effort but DD is still happy she's baked for Santa. If time IS on our side, we'll do it from scratch. I'm normally in the kitchen anyway with the other 2, as we work together for 25th to peel veg and potatoes, make giblet stock, make the stuffing, and also organize that night's dinner and start to unwind as a family slightly.
DD's birthday always has a present wrapped in birthday paper, a card, and a birthday cake. Lots of people, even when they do a separate present, wrap it in Christmas wrap, and she does notice that. Many years, the cake has been chosen by her in M&S on 24th, and sometimes we have known we would have time to bake it at home - but as we bake together at other times, DD is happy to have an M&S cake as Christmas is busy.
One thing - don't get so caught up in WINDERFUL ideas in year 1 or 2 that are then difficult to keep going for years more to come.
We don't do Elf on a Shelf cos I knew I wouldn't have time to organize the chaos every night. But I do have a fabric hanging advent calendar - I get enough chocolate pieces in nets (M&S, Aldi etc) before December to fill each day, I have a very long list of ideas for things to do on less busy days (various outings, tidy DD's bedroom, learn some christmas songs, making Christmas crafts etc) so I might put a note or a clue to an "adventure" in the pocket on those days that I can do something citing, but I also used to print out a lot of free printable colouring and activity sheets from the Web for other days and roll those up to put in