If I did this right (video editing is not my strength), it’ll walk you through the process for using resincrete to make a bowl (I’ve used these as candy dishes, but they’d also work as trinket dishes, candle bowls, etc.)
Resincrete is non-toxic and non-flammable, so a pretty good option for this kind of thing, and something you can safely do with kids, without the need to mask and glove up as carefully as you need to for resin.
It also gives a fast result — a few minutes working time before it starts to set, 30 minutes until you can unmold, and 2 hours to fully cured. I’m planning to try concrete sometime soon, but I do like the smooth, ceramic-like finish you get with the resincrete.
It’s a similar look to plaster of Paris, which I also haven’t tried yet, but is supposedly more durable. I find that when I use it for thin pieces, it breaks apart immediately if dropped (resin sometimes survives dropping, or just gets dinged a little, which can often be fixed with sanding.)
One note — the white does seem to mark up fairly easily, so handle it carefully, or you may end up needing to do some sanding to get back to a white finish. It can take some resincrete pigments to change colors, but so far, I’ve liked the basic white best.