It's totally ok to do your own thing. No two households do it exactly the same.
We use actual M&S stockings (without any sexy lace, just plain stretchy 40 dernier black stockings) so the volume if gifts is approximately similar to an average adult human leg. We own twice as many stockings as there are people so that each person can place an empty stocking at the foot of their bed when they go to sleep and it is magically replaced by a full stocking while the receipient is asleep (you don't want to be actually stuffing a stocking during a 2am "I've woken up cos I need a wee, so might as well do the stockings while I am up" - they are packed and stowed during the preceding few days.
Always a £2 coin, a satsuma and an unboxed Terry's Chocolate Orange in the toe. Then the rest of the volume will be around 20ish items evenly divided between the broad categories of "something you want, something you need, something to eat, something to read" plus "something silly" which doesn't fit into this rhyme. Each will be wrapped but wrapped in a slapdash manner with cheap paper, not presented nicely like the under-tree presents
Want - at least one small cheap item from the recipient's wishlist (other items from the wishlist may be bought by relatives and be under the tree not "from santa"). Often might be a DVD of a film etc, or a small lego set.
Need - anything that would be just bought from the household budget if needed any other time of year is fair game. Typically socks, pants, pyjamas, school stationery.
Eat - chocolate bars, perhaps a toblerone, nuts, candied fruit, turkish delight
Read - at least one magazine, rolled up. At least one book. More likely 2 or 3. May be from wishlist or may not be.
Silly - a few things that are in the general category of " Stocking Fillers" - maybe a game or toy but unlikely to be more than £8 ish per item, no more than 2 or 3 things in this category.
Adults get a stocking too for we have also been good.
The point of a stocking is to be opened and enjoyed as soon as the recipient wakes up in the morning. Tree gifts from each other and from relatives get opened much later in the day in the runup to lunch so stocking gifts are to get the ball rolling on feeling Christmassy in the gap between waking up and pre-lunch champagne.
Other families may use pillow cases, or large sock-shaped sacks which aren't human-leg sized, and will have different traditions for what goes in. There's no general rules.