One thing I was taught and figured out on my own was to accumulate most of your wealth in tax-advantaged retirement and education savings accounts. For a middle-class household, all of its intangible wealth should be in those accounts by the time the person or couple hits 60.

When we were 50, we started making "catch-up" contributions to our retirement accounts. We actually re-fi-ed our mortgage, starting over with a 30-year schedule, to have more cash for contributions.

My main retirement account has an S&P 500 index fund. For a long time, I'd jump into it after the market tanked, ride the bounce back up, and then get out and wait for the next tank. That worked well for a long time. But, tanks were far and few during the Trump years. We were mostly out when the COVID tank hit, and then we got back in and rode the rebound. So, we did really well in 2020. But, because all of those gains were in out retirement accounts, we still got our stimulus checks. They really didn't make much difference, but it was fun screwing the system.