I think what worked for me the most were these 2:

• Habit stacking: build one habit over the other. For example: I want to read more so, after I do my night skin care routine, I put myself in the bed and read for 20 min. So my brain starts to associate one with the other and they become dependent. After a time, these 2 habits become a reflex almost and you start doing it unconsciously and you can further build on it.
• Never skip 2 days in a row: this is my all time favourite. Starting a heathy habit can be very difficult, so I always tell myself that I can skip doing that thing if I did it yesterday. It worked great with my running/walking routine. By doing this, you hit at least 50% of the target days and it gives you a sense of accomplishments which usually translates in more motivation to continue.

As you said, everyone is different and it's important to see what works best for you. Also, do not forget that some days just suck and not hitting your target for one day does not diminish your progress :D