But, there are things that you can do where you will not ALWAYS trade your time for money. That should be the goal. I call that passive for me. But don't focus too much on the word itself.
Some ideas:
- Create a SAAS. It can bring money where you don't always trade your time for that money BUT it requires time to do support, maintenance and enhancements. You can decide how much. Lot of small products that are doing under 10K per month with not a lot of hours spent per week.
- Write a tutorial/E-Book and sell it. This again can generate income for which you won't always trade your time. But it has a huge upfront cost.
- Work an extra job during weekends. Not recommended but it technically answers the question "how can I generate new sources of income". Silly answer but technically correct. Of course, you are trading time for money 1-1 with this one.
- If you are good at something but cannot a tutorial/e-book, then offer your service live for a fee over the phone or skype etc. Live coaching, tutoring, code mentoring etc.
Note that all of the above requires marketing efforts specially in the beginning. You cannot magically expect people to find you and pay you. The "find you" part is the critical one where a lot of us fail.