‘Never invest in a business you cannot understand’ was one of many of Warren Buffets famously quoted rules of investment.
What rules do you consider essential knowledge? Maybe there are some clichéd rules you find misleading? 
When investing, capital at risk.
Do your own research. Its a huge risk and you need to be sure about the legitimacy of the investment. Most investment make a lot of promises and people jump into it. Research is key.
Rule 1: Don’t lose money
Rule 2: Repeat Rule 1
Never invest more than you can afford to lose. There are no guaranteed profits.
Probably the most famous cryptocurrency investment rule! Welcome to the Pynk forum Karen it is great to see you here. You are very welcome 
When investing, capital at risk.
I’m here directly because of you, Al. Thank you!
Be disciplined with your hard earn money.
Have interest and passion in what you invest in.
Show no emotion when you trade.