There's one piece of investment advice that will do wonders for your returns but is really hard to follow: It's to go against the crowd.
Buy when everyone else is reticent, hold on to investments through periods of shakiness and sell when everyone else is becoming very excited. It makes sense when you consider it objectively. Why would you want to pay over the odds for an investment that everyone else is clamouring to get into?
But when you try to put it into practice, it can be harder than you expect. Looking for bargains in a depressed market might not be too difficult but it takes steely determination to hold on to them when prices fall further.
Data shows that individual investors do more poorly than the indexes they are invested in partly because they time their purchases and sales badly. They sell at low points of the market and buy back in once some of the gains have already been made.
If you cave and bail out during a rough patch you solidify any losses that until that point have been only on paper. If you can stick it out and ride it back to the good times, you will end up much better off.