The greatest rule of investing is to not take investing advice unless from trained professionals like stock brokers. The reason being; choosing to invest is a subjective experience with too many wavering parts to follow anyone's know-how as a direct path. So rather than giving "advice" consider the following as simple tips to look out for when investing.
Time in The Market > Timing The Market
Read that again. Losses are temporary if your investment succeeds and, while it may be tempting to back out, taking a look at the yearly dips in your investments will likely reassure you that you are in good standing.
On the other hand, somethings your investment timing just isn't good but and you'll be okay. The market is a crafty ventriloquist, don't let it tug at your insides.
Don't Buy High
When the stock market dips, see it as a time to buy at a better price even if you didn't get in on a project early. Consider these dips as second chances and, don't let them scare you off. Oh and, always invest in fundamentals and not anything that the internet is buying as the hype.
Speaking of Hype, Don't Buy-In
Don't let the market consume you. Take some time off obsessing over your investments and step away from the tech. You'll be more productive. Remember your investments are important and can potentially change your life but they aren't your life!