1) Keep it niche
You come to trust a person to have something to say about 'x' rather than the entire alphabet.
2) Keep it fresh
Depending on your ambitions update twice a day Yes, you have to have a point of view, no you don't have to make the posting public but you need to build a 'body of work'. 250 words will do, a picture and comment and from time to time a link and snip from something you have stumbled upon.
3) Keep it authentic
There's a light, conversational style that i think of as 'BJ' (Blog Jocky).
4) Read and comment on blogs you like
Reciprocity is vital, there is a virtuous circle of being read and contributing to other people's blogs. Vary the pace and approach. It works to include photos and video, though you risk setting yourself too great a task if you imagine you can generate or load a video clip every time.
5) Watch the stats
You can understand what makes your blog tick, what keeps it vibrant. It is motivating to know you are being read.
Put your content in front of those who are most likely to find it of interest or value by sharing it with specific Linkedin groups and by getting it out on Twitter as part of pertinent conversations.