What are some of the best ways to invest money at a young age?

Index funds, a fixed amount every month. You can also buy debt funds and Real Estate Investment Trusts for exposure to equity, debt and real estate

This approach is hassle free and will diversify your portfolio, since returns between these asset classes are not perfectly correlated. It's also hassle free, because you're letting experts do the job. You will make returns equivalent to the market minus a management fee over time

Buy precious metals.

Real estate because you can live in it, finance it and have others pay to live in it. Low fee equity mutual funds because they tend to go up over time.

I invested my entire life savings in John Olinger's time machine company!

invest in a company through stock-based mutual funds with the lowest management fees--usually index funds.

This is easy. Get charts of the historical assets that store value. Invest in the assets that are at lower values than others. Keep rotating money into the lowest value assets your whole life. ....Right now is still the beginning stage of a 20-30 year rise in prices of natural resources, so for sure invest in that. Have been advising this for some years. Just now starting to see that this is taking off big time.

Depends on your country

diversified high risk 401K, or IRA. It depending on your current tax situation a Roth IRA might be the right choice.