1) Blog for yourself and no-one else. Write things up because you find them interesting or you learned something. Trying to second-guess things like what will be popular or get engagement is not a fun time for what is likely to be a hobby.
2) Keep it low maintenance and simple publishing process. I use Github pages and Jekyll, but other similar options are available.
3) If you're doing technical content, try to have practical examples. I've had multiple times where I thought I knew how something worked and, in the process of writing a blog with practical examples, found out I was wrong about how it worked!