Why at-home parties go wrong
Almost always the same reason: there is nothing holding the middle hour together. Children arrive, eat, and then there are forty minutes where nobody knows what happens next. Every idea below has a spine.
Ages 4 to 6
Keep it to ninety minutes and keep it physical. A decorate-your-own crown or wand table, a simple treasure hunt with picture clues, and a dance section works. Pamper parties work at this age too, as long as they are pitched as dressing up rather than treatments: foot spas, glitter tattoos and silly hair go down far better than anything careful.
Ages 7 to 9
This is the sweet spot for making things. Lip balm making, bath bombs, decorating a cake each, or a pamper party where they do most of it themselves. At this age they want to take something home that they made, not something they were given.
Ages 10 to 12
Tweens want it to feel a bit grown up without being babyish or actually grown up, which is a narrow gap. Perfume making, a make-up bag to personalise, a polaroid camera and a wall to stick the photos on. A sleepover works if there is an activity anchoring the first two hours.
Food, briefly
Do it at the start or the end, never the middle. The middle is where the party lives.
If you want the whole thing taken off your hands
That is what we do. We arrive with everything, run two hours of it, and pack it away again. You get the photographs and none of the clearing up.