Choosing the best way for steady income depends on how much money you have and save each month.
Seems like you are a busy person - try using some investment funds / your intelligent friend-trader. Yeah, it's not easy to find smth worthy, but the future benefits are high if you do spend some time on it.
BUT if you can afford to take some risk, I highly recommend investing in start-ups. Sure, you've heard about ICO and stuff. Lots of interesting projects out there (any many scams).
Conducting serious due-diligence of these projects (or paying someone for it) is like a gold stick for investor.