Once you are comfortable with your foundation, then it's time to "consider" more risk averse investments so you can retire both "early" and "comfortably". I look at the 401K and ROTH IRA and ways to help you retire comfortably.

Mutual Funds, Stocks, Flipping Property....if effective all nice ways to try to get richer sooner rather than later.

Stocks- Honestly this depends on your comfort level and understanding with the types of stocks you invest in. But do a lot of due diligence and UNDERSTAND what the market is if you are going to do this yourself via the net.

Starting in the mid to late 90's I began heavily investing in technology. Owned stocks such as Cisco, AOL, Yahoo, Applied Materials, Broadcom, DELL etc............keep in mind I wasn't nearly early enough on any of these to be one of the rich guys you read about as these were all well developled companies when I bought them with the exception of a few.

I had a slightly below average understanding of the stocks I owned, and an average understanding of the stock market..........but I thought this was flippin easy because when I started investing we were in the Internet Craze.
Problem was I believed I was going to get rich off these and didn't understand when to sell.

I invested about 20G and watched that multiply by over 4x and bragged to my wife that my goal was to make 25% a year on the annual investments. Even had an early age targeted for retirement and arrogantly showed my wife that the balance on our stocks was more than our mortgage balance. And it worked for a couple years. And then it all crashed. And over and over and over I told myself "it can't go lower". And it did....much lower.

In the end, I only made a very small profit on that investment because truth be told, I didn't know nearly enough about what I was doing to handle online long term investing.

Mutual funds, to me are clearly safer; stocks..which are still my personal interest....can great reward or greatly disappoint. But be sure you know what you are doing if you are doing it on your own.