I really don't think that there is any specific way to write a blog. Blog is supposed to be like a journal where you can either keep track of what you are doing in life, share thoughts and express yourself or about your brand.
I personally prefer blog that are written naturally. I never plan to write a blog, also I never do iterations to edit my blog. I just write it and share it as it is. Simple. I think this approach works really well for individual blogs but for companies they may prefer doing reviews which is fine but I still feel blog should be free flowing with your thoughts and ideas and it is a place where people connect with you.
So don't follow any rules. Written whatever you feel like writing. Enjoy.