Purchase a garden flag and a garden flag post. You can find these items online, at specialty boutique stores and at home construction stores. You also can custom design them online.
Install garden post. This is an easy step. A garden post has two main parts. It has a vertical post that you push into the ground. At the top of that post, it is crossed by a horizontal post that holds your flag. To install the post in your garden, simply hold the post vertically and push in into the soil. Push deep enough so that the post stands straight and feels stable.
Slip flag through garden flag post. At the top of the garden flag is a "tunnel" opening running horizontally across the border. This is an opening for the horizontal part of the garden post. Simply slip the horizontal post through the opening at the top of the flag.