Only invest money you do not need for 5+ years.

Sounds simple.
Most people ignore it & blow up their portfolio.
If you might need it in 2 years... CD or bond.
Not the stock market.
If the market drops 40% right after you invest & you need that money in 2 years you are forced to sell at a loss.
The market does not care when you need the money.
The right way to make your money work:
Every dollar after bills are paid.
Every raise & bonus.
Every dollar of put premium.
Anything you can let compound for 5+ years
Time horizon is risk management when you hold quality companies at good prices.
Non-negotiable