This is one tip that I think that is especially hard to follow, especially for new investors.  It can be fun to check your stock, investment, retirement portfolio every day or every hour to see how much money you “made” or “loss” that day.  While it can be fun, it can start playing with your emotions and your judgment.  When you buy an investment it should be for the long term and you should accept the fact that in the short-term (especially if you invest in stocks and mutual funds) that your investment will go up and down for no good reason (sometimes significantly).

“In the short run, the market is a voting machine but in the long run it is a weighing machine.”
– Benjamin Graham

The problem with watching daily fluctuations or reading daily media reports on your company is that you start thinking that these fluctuations are actually nonsensical and that you should take some action on these fluctuations to make or save yourself some money.  This will eventually result in you making rash decisions to possibly sell an investment or run up a bunch of commissions because you are trying to play the market.

I personally think you should be investing for the long-term so my personal train of thought is that if you don’t plan on holding onto an investment for at least 10 years you probably shouldn’t be buying it in the first place.

“If the job has been correctly done when a common stock is purchased, the time to sell it is almost never.”
– Philip Fisher

So save yourself the trouble and just rely on your monthly investment statements to keep track of your portfolio and even then don’t get too worked up if a single investment or your entire portfolio rose or fell by 20%.