Make your newsletter reflect your personality. You're not writing a script or poem, you're writing a letter. It should read as a casual conversation between you and a friend. Think of it as sitting and sharing a cup of coffee with someone and you're telling them about your life for the last month or so.
Don't go wild and add everyone you know to your new email list... there are rules and laws around this practice and you could find yourself in receipt of a huge fine... and I mean HUGE!