On my next one, I started with Bunzo (in sepia) around my first square, then had visions of painting a mountain scene with watercolors on the inside. After the delusion of being a watercolor artist left (have never painted anything in watercolor, let alone a scene) I thought I could do a little zentangle garden. So I used watercolor to paint the background and used a sepia pen to make my garden. I highlighted it with a white charcoal pencil and I added circles with a white gel pen. (Not sure I like the circles yet)
If you haven't seen some of the beautiful zentangle frames that Maria Thomas has made, make sure to check out these to links....a-frame-of-mine-d and bordering-on-reverie. These posts are not the first time Maria has shared her beautiful zentangle frames. If you search back through the zentangle blog you will find more.