3. Mutual Fund Investments
Fidelity also has zero-fee funds that allow you to have zero fees and invest with their index funds as well. Some of these can be like FZROX, which is similar to VTSAX over at Vanguard.
5. Employee Sponsored Retirement Plan
It can be as easy as a 401k plan that allows you to meet the company match. If the company offers a match that is free money provided to you, take advantage and invest with the 401k.