My little one goes to a Montessori school, a good one, but I still feel the need to do some homeschooling, very informally. That involves mostly reading (no compromise on this one), writing, etc.

I've signed him up on synthesis.com (team and tutor programs), it's a great resource for developing problem solving and teamwork skills.

An underrated skill imho is just to have conversations with them, listening to them, and keeping asking questions. It strengthens the bond while developing their imagination and thinking abilities.