For retirees who are looking for greater capital appreciation and hold a higher risk tolerance, an ETF portfolio with a more aggressive investment strategy may be a better fitting option.

Investors looking to solely live off their investments over the next 20 or so more years will want to included investments that will appreciate while still hold their stability, according to Christine Benz, Director of Personal Finance at Morningstar.

ETFs are low cost, tax efficient and easy to use investments that allows individuals to take control of their investments.

An aggressive ETF model includes half of its assets in stocks and the remaining half in bonds and cash. Investors will also follow a total-return approach and allocate holdings into cash to cover living expenses.

Retirees who also accrue income from Social Security, pensions or a business may also consider taking on additional risk with heavier weighting in equities.

This type of portfolio includes separate ETF bond holdings, including iShares iBoxx $ Investment Grade Corporate Bond (NYSEArca: LQD) at 12% and the mortgage-backed bonds ETF iShares Barclays MBS Bond (NYSEArca: MBB) at 6%, to replicate securities in a total market bond index fund.