Most banks, credit unions and brokerage companies offer pitifully low rates on your savings accounts. You often have to squint to see if there is any digit beyond the decimal point and the zeros. CD’s have other restrictions.
I like (and use) this idea: Put your money in a short-term U.S. Treasury bill (T-Bill). You can set this up easily online with TreasuryDirect.gov (use Chrome or Explorer). There is extra security, which I appreciate. The site links to your bank. (Just don’t link to accounts that restrict distributions, such as an IRA.)
You decide how much to invest in one of the weekly periodic auctions. You can invest as little as $100. I like the 4-week T-Bill, which is paying about 2.4% (annualized) now, and you only tie up your money for 28 days.
Once the T-Bill has been issued, the Treasury deducts the amount from your bank account. At the end of the term, your initial investment plus interest earned is put back into your account. The Treasury site explains it all. Let me know how this works for you!
Bonus: Earnings are free of state and local taxes.