• Create a text box outside the page’s text frame.

• Add your callout text.

• Tweak the callout text box to suit your design. For convenience, I created an Object Style named “Callout” and defined the Fill, Stroke, Stroke & Corner Options, Paragraph Style, Text Frame General Options, and Drop Shadow.
  Note: You will also want to define the Anchored Objects Options if you want the callout to move with the surrounding content.

Click for full image.

• Position and resize the callout. I also dragged a ruler to the center of the callout, but you can ignore that if you want to make your callout pointer off-center.

• Now we’re going to create the callout pointer. Left-click and hold on the Pen Tool and select the Add Anchor Point Tool.

• Along the bottom of the callout box, add anchor points at the center and two points equidistant to either side.

• Select the Direct Selection Tool.

• Select the middle anchor point and drag it to the appropriate spot. You can also select the other two anchor points and adjust them.

If the callout box is giving you trouble with word wrapping, table borders showing through, or other layout issues, you can drag it to a higher layer. If you do, remember to move it if the content on the lower layer moves.

If this has helped you out or if you have anything to add, please shoot me a comment. And if you find yourself taking a photo with Lisa Thorne, don’t stand in front of her.