list-style-image

These are html tags you type.

    <ul style="list-style-image: url(arrow-small.gif);">
      <li>first</li>
      <li>second</li>
    </ul>

I like this.
I can use MS paint, change the view to a large magnification, and draw a small image.
Drag the corner of the background, so it is not much larger than the image.
Save it as a gif image in your directory.