A bit of history:
Blogging began in 1998 as a form of online journal — as such it's OK to say what you think. Bloggers tend to have opinions; otherwise most of them wouldn't have blogs. Blog readers want to know their opinions; otherwise most wouldn't read blogs. Being a former journalist myself, I know it is OK in a blog to "ease up" on the journalistic “objectivity” and say what you really think. In fact, it's preferred.
Engage from the beginning. Blog readers generally pay attention to the title and the first two paragraphs of any given post, and then decide whether to read the rest. This means your title, and your first two paragraphs are your chance to entice them to read the rest of the post. Humorous, playful, and even whimsical titles are OK because they catch readers' attention.
In the first two paragraphs, try to give the reader an idea of what you're talking about, what you think about the subject, and — towards the end of the second paragraph —work in a teaser to get them to read more.
Be casual. Try to write in a tone that's natural, casual, and almost conversational. Imagine that you're writing for a guy who's sitting in his cubicle during his lunch break, or in his pajamas before bedtime, looking for engaging conversation online.
It's a conversation: keep the discussion open. You don't have to tie up all the loose ends and answer all questions by the end of a blog post. In fact, it's better to leave some questions asked and unanswered. If the first few paragraphs of a post are the open door inviting readers into the post, the last couple of paragraphs are the open door inviting them into the conversation.
It's personal. People don't just read a blog; they respond to it by leaving comments or linking to it from another site. People also inherently connect not just to the blog but also to the author. Blogs live, breathe, and die based on the level of involvement with their readers and other blogs.