I'm in.
Brain:
Read 12 books (one a month) that are not rereads of old favorites or kids books.
Refresh Spanish and learn French (with the kids!).
Do a self-study course on drawing (one/day for 30 days) then practice 2x/week.
Restart study course I dropped mid-stream.
One art project per month. I love this one...it'll be in addition to the art I do with my kids for their school and the drawing.
Health:
Experiment with intermittent fasting (considering eating every other day). Switch to much less processed food.
Keep up running through the winter to maintain and retrain for a half marathon in October. Finish this one by actually running, not walking, most/all of it.
Stay off caffeine. It wrecks my sleep!
Experiment with reducing eliminating sugar to find the sweet spot (pun intended).
(Edited to add) Walk dog 3-5x per week.
Finances:
Stay out of credit card debt.
Calculate our FI number.
Build emergency fund to $10k of easily accessible money.
Build our home business.
Stretch: restart contributions to IRA.
Reevaluate budget and stick to it (revisions allowed).
Relationships:
Write my friends more often - at least once every month.
Complain less...practice optimism.
Visit a few people that we haven't seen for a long time. Set up special budget contributions so this can continue.
Read one classic kids novel per month to the kids. Resume playing board games at least once a week. Continue to do art projects alongside them.
And household, I'm going to steal from Rosy:
Keep on de-cluttering again and again - it is a freeing experience.