If you enjoy investing and can spend some time learning about trading options, it can provide a nice income stream in a taxable account. Somewhere around 0.5-1.0% income a month is possible and reasonable without taking on extreme risk. Income from options on indices or futures is subject to 60/40 long/short term capital gains tax and really helps keep the tax costs down.
That said, the only riskless options/futures trade is called a “cash and carry” which essentially earns you the risk-free rate and isn’t much better than buying a treasury note. Also with interest rates so low, you’re more likely to get like 0.5% per year rather than per month