In our house, stocking has something from each of the 4 categories of the poem and some categories more than 1 item. (Next bit not in order sorry).
Something to read - 1 fiction book that they would enjoy, maybe a factual book for older DCs as well that they’d be interested in.
Something to eat - fruit (a crunchy apple, mandarin, kiwi fruit and a green banana) and some sweets for each person. (Having our “own” selection of fruit is a big treat going back to our own childhood when it included both a red and a green apple).
Something you need - nice socks, hair bobbins, nice knickers/underwear etc - maybe character or colored ones if mum and dad normally buy plain, etc or twist able crayons rather than regular ones if a school pencil case might need replenishing, water bottle with a favorite character...
Something you’d like - this could include crafty bits, small toys, collectibles (Match Attax cards, Lego figures..), mini slinky, “grow your own crystals” kit for older dcs, pocket money toys if they don’t normally get those (little spinning tops, stretchy men, dinky cars...)
Baby could have bibs, soothers, a board book, rattle, and a carton of emergency formuLa for out and about (even if you be, it may well be handy to have 1 ) or something long-life for when they start to eat (dried baby rice might fill up space?).
Sometimes, for older dcs (from toddler age), a reading thing that takes up space such as their favorite magazine, especially if it has something to do on the cover (mini toy or craft kit etc) can be useful to occupy them for a while.
Each DC gets part of something to play together? So a different colored ball each or each gets 1 beanbag/ball from a juggling set of 3?, or a set of paddles and a table tennis ball split between older ones?