Spiffytastic's 6 Rules of Crypto-Investing:

Rule 1) Don't be greedy.

Rule 2) HODL does not mean never take profits.

Rule 3) Fight the urge to FOMO. Don't buy at All Time Highs (ATH)
It's better to just miss out than get caught holding the bag.
A coin with good fundamentals will eventually dip. Buy the dips.

Rule 4) Because a coin/token has pulled back from an All Time High does NOT necessarily mean it is a good time to buy in.
A coin which got pumped unreasonably in the past does not mean it will be again.
Don't FOMO, but don't also buy cheap junk.

Rule 5) Cut losses early.
All investments will not moonshot. Some may go down or stagnate.
Better to get funds into what is making you gains.
Better to lose .5% trading fees than always HODL.
If you get caught holding the bag, you may never see that $ again.

Rule 6) Do not invest more than you can afford to lose.
Similarly, do not invest on credit.