Racking up rewards on checking accounts can substantially boost earnings.

"You can easily get up to 3 percent rates on up to $25,000," Tumin says. Some FDIC-insured banks recently paid even more, such as Southern Bank, which is based in Missouri and paid an annual percentage yield of 5.01 percent.

The trick is clearing the checking account hurdles, which can include: meeting monthly minimums on the number of transactions, using online rather than paper statements and switching to direct deposit. "These debit card transaction (minimums) are starting to go up," Tumin says. "Now, it's 12 a month, rather than 10."

McBride says that if you don't meet account restrictions, you'll earn a substantially lower rate. Still, sometimes there are rewards other than a better interest rate. Some companies like Capital One offer frequent-flier miles or merchandise on rewards checking accounts.

Overall, Tumin says if you're willing to jump through some hoops, rewards checking accounts can be profitable and easily found. They're offered at credit unions, big banks and even local banks.

"In the past two years, the best deals are on rewards checking accounts," Tumin says.