1. Do not invest in things you do not understand.
2. Do not invest in things you do not believe in.
3. People feel the impact of "loss" more strongly than "gain". Do not be afraid to earn less, be afraid of losing more.
4. People who encourage you to invest will not pick up the tab for your losses.
5. Stay away from excessive confidence and herd mentality. Focus on long-term returns. Do not indulge in short-term gains.
Most importantly in investing, is being able to sleep well at night. Things that are eaten with a worried heart are often not very good.