I make sure I cover all 4 elements in the stocking, but not just 4 gifts.
Want: Fun stuff, things she has asked for, usually her big present, often a joke, maybe a small puzzle (she likes those) or something to add to collections (lego, Match Attax cards 1 year, extra food for the kitchen another...).
Need: nice knickers (she likes a particular type), hair bobbins (we always need more!), nice socks, etc. Small things that are useful and help take up space - maybe 2 or 3 items. Craft consumables can also come under this heading, as pencils, paint, stickers etc get used up (I often find some nice unusual ones in the National Art Gallery shop, which I wouldn't be likely to buy in the normal course of events - still for DCs, but that bit nicer).
Eat: red apple, green apple, orange, green banana, and 1lb box of sweets (tradition going back to my Christmas stockings).
Read: Between 1 and 3 items normally. Always at least 1 fiction book (maybe 2), to try and instill a love of reading. Often an Annual or festive edition of a favourite Comic or Football magazine as well. And sometimes I find a nice non-fiction book of relevance - so DD is now very involved in sailing so last year there was a sailing tactics book in her stocking as well as a story (fiction). But I give books to DCs a lot (nieces, nephews etc) as part of presents and always remember the joy of a new book all for my own at Christmas (rather than just for a week from the library).
DD will be 13 this Christmas, but I've been doing this since she was 1, always making sure there was something practical, something to eat and something to read in her stocking as well as fun stuff. And she has always enjoyed her stocking - not always every single thing in it, but most things.