You need this:
- Wooden plant plugs (garden center)
- masking tape
- Acrylic varnish in different colors
- brush
- black decorative marker or felt pen
- Metal basket in antique look
- moss
- different herbs
And this is how it's done:
1) Cover a surface on the plant plugs with Malerkrepp (DIY store) and paint in color. Allow the paint to dry well and then label the plugs.
2) Lay out a metal basket or other large container of moss (florist). Plant various herbs (here thyme, sage and rosemary) and water.
Here is the instructions for download.