Best advice that everyone should learn

This is the advice that I taken from theStar newspaper:
theStar advice on investment

From my experience, I can tell you that this is very very good advice. Let me
quote part of it:
"In our experience, in most cases, the moment we feel like buying stocks is the best time to sell them while the moment that we feel like selling them is in fact the best time to buy. We can apply this contrarian theory quite successfully in most periods."

And part of my experience got to deal with feeling of regret and here is the advice:
"One way to minimise the feeling of regret is to stagger our purchase and selling. We will only know the peak when the market starts turning downwards and vice versa. Therefore, by staggering, we will have an averaging effect rather than taking a one-time hit, especially if it is at the wrong timing."

I think 99% of the time you will be earning money with this way.