Having one or two go-to ETFs to invest in every month can make investing a breeze and save you a lot of time. The key is, however, to find some solid ETFs you can trust and feel confident about, knowing that you're putting your money into the best fund suited for your strategy.

Investment management firm Vanguard offers a variety of exchange-traded funds (ETFs) that allow investors to target a specific theme or sector at a low cost. With just 0.04% expense ratios, meaning $0.