I think the most important thing on the list, is betting all your money on one project, if you bet big on one horse and your horse end up losing that is game over for you, there is nothing like risk free investment in the space and anything can go to Zero
Deversification is the most important thing when investing. Moreover, it will be correct to diversify your investment portfolio not only within the crypto market, but also in the environment of other markets (for example, such as the stock market, gold, etc.). Then you cannot be with nothing at the moment.