Cheesecake I think it depends on the size of the stockings you have, and when and where you want to give them.
When I grew up, my dsis and I had stockings that were made from an old pair of our red tights with a knot in one leg that got lower each year as when I was about 2 I had a freak on christmas eve when my mum got out one of my dad's old rugby socks to use as I thought that Santa would think I was a boy - so last minute solution was needed. The tights got used ever after until I was at least 30 and are still in my mum's christmas box of stuff. We would have them in our bedrooms to open in the morning and be full of things to keep us quiet so we didn't disturb our parents too early 
and would be finished off with a satsuma in the toe and bag of chocolate coins which we were allowed to eat on the understanding that once they were gone, that was it, and if we were sick then we had to clear it up ourselves and it was our own fault!
I also do this for my dc although no longer bother with the satsuma after discovering one festering a month or two later hidden in the depths of ds1's bedroom! I tend to put in
- a toy car or two
- a comic (that often has its own toy on plus fills up space cheaply!)
- a small pack of crayons or colouring pencils
- a notepad or memo block
- a new pair of pants and socks and a vest, so they are conveniently ready to wear that morning (rest of the packs get wrapped up and are under the tree)
- a couple of silly things like finger lights or those stretchy dinosaurs (last year there was a light up meteor ball from the sainsburys half price toy sale - they have some good bits for stockings)
- a small pack of lego (again, either from sainsburys half price sale or the lego shops often do christmas themed bags for about £3 which squash in well)
- chocolate coins
My basic rule of thumb is if they play with it in their bedrooms or on my bed on christmas morning, can they do so safely and without causing any mess or damage (hence crayons rather than felt tips for example) or noise (being woken by a chorus of kazoos early on christmas morning when you have been up late finishing the wrapping is not the most joyous way to start your day - done once, never again...).
I end up having a nice lazy christmas morning as the dc are happy to have their stockings and play with the stuff in them, stuff down nibble on their chocolate coins, then we have a lazy breakfast, clear away, get anything needed for christmas lunch to be done early done and we can have a nice couple of hours unwrapping presents from under the christmas tree.
My sister on the other hand has massive stockings that were given to her dc by her PIL, made by her mil, because it was the way they always did things and her dh was adamant that santa wouldn't come if it was done any other way or that he'd thow a massive strop if it wasn't done his way. It means all their big presents are in them, they just a few bits under the tree. It also means that as they are early wakers, they are desperate to go downstairs to get their presents and wake their parents up early, there's a mad rush of unwrapping everything, everything seems to be from santa, dsis misses half of it as she has to pop out to check on breakfast and get the early stuff for xmas lunch done whereas if bil has to pop out to do jobs on the farm then everybody has to stop so he can see it all, apparently it's different if dsis misses things because she is still in the house 
The rest of the day then seems to be a bit of an anticlimax - all the big stuff has been done by breakfast time before getting dressed. I know I'm probably biased as to why I prefer my way of doing things to the way BIL does them but having spent christmas with them a few times, our dc are much more relaxed about it all and have a much more fun day as a result of getting their presents spread through the day (Santa obviously does the right sort of stocking drop off regardless of where you stay and what the host's traditions are!).
But it's definitely worth working out now while your dc are still little how you want your day to work, what used to work well when you and dh were young and what you liked or didn't like, so you can create your own christmas traditions that suit you perfectly...