5. Never gamble with money/crypto you cannot afford to lose, Or never ever gamble
This is just theory to many people, in practical sense, many people are gambling with the intention to double the money they have. They see gambling as a way to make money.
7. if you hold big amount then apply every kind of security available, to keep your keys safe.
Do not wait until you have a big amount in cryptocurrency that you're holding before you decide to take your security seriously, with any amount of bitcoin that you have there is always a plan to get more, hijackers can be patient till when you have gathered enough BTC maybe through DCA, before they steal your bitcoins. Take your security seriously with any amount of bitcoins that you have, the earlier you get used to keeping your bitcoins safe the better for you in the future.
8. Stay away scammy schemes
Scammy schemes are the "too good to be true offers".