To write a comment on someones page you have to go to the bottom of their blog and at the reply section where is says reply to the post. Then once you get their write a good quality comment then post it.

When I get a comment from someone I expect that it will be a formal and good quality comment. First the person should say hello and introduce themselves. Then the person should try and express interest in your topic and try and make a connection between you and the other person.