Help them remove the stigma around their bodies and sex, and empower them to speak and be heard when something they don’t like happens.
This. So much this. If auntie wants to give them a kiss and they don't want to get slobbered then tough fucking luck auntie, I'll back the little shits up when they bite you. Predators are, by and large, able to do what they do because people don't teach kids that they do, in fact, have bodily autonomy.
And while I'm at it bodily autonomy of kids also implies that parents don't parade photos around like some fucking trophy or something. Have some basic fucking regard for your own kids and what they want. How would you feel when they're showing nude pictures of you to their classmates yeah I thought so.