Ask Lemmy

Just off the top of my head:

• If It's at all possible, retire early! Look into FIRE (Financial Independence, Retire Early)
• Carry as little debt as possible
• Max out your 401k (otherwise you're leaving money on the table!), build a savings account, and maintain at least 6 months' expenses worth of cash in an emergency account
• Where you can, plan ahead for large purchases (e.g., vacations, new roof) and make them in cash instead of financing them
• Minimize consumption of goods to maximize financial power (i.e., don't get sucked into lifestyle creep!)
• Do spend money on things that are high-quality and will last
• Lift heavy things often
• Don't skip cardio
• Hydrate!
• Use sunblock (physical >>> chemical)
• Get your routine medical stuff (e.g., mammograms start at 40), even the uncomfortable ones (colonoscopy!), and don't wait until minor things become major to get them checked out
• Be calm, rational, and intentional in your interactions with others, and if you've behaved poorly, give a heartfelt apology. This is especially important with your significant other.
• Pay closer attention to your parents' needs - they are aging and will start to need help they may not be willing to ask for
• Don't be afraid to remove bullshit from your life. That one "friend" who you never want to hang out with because they just drain your energy? It's OK to let that friendship go.

I don't have kids so no advice there.