Be concise. Be on point and direct, no need to remind people that your opinion is just your opinion. Avoid vagueness (maybes & sometimes). Favor simplicity and use plain phrases, you are there to convey ideas not to showcase your language mastery. Write a draft and do reread it.
My understanding is that you're doing a creative graphical job ? What would the blog content be about : just a portfolio ? Your work process and principles ? Opinions and musings related to your workfield ?