Supplies you'll need:
Rectangular 'Styrofoam' box ( Not truly styrofoam, its more squishy. It's actually EPP, expanded polypropylene. Thanks macrumpton! I got mine out of a laptop box, it's used to protect the ends of the laptop)
Thin strip of cardboard
Potting soil or Dirt
Herbs ( You can use seeds, but if you already have herbs growing outside, there are probably baby ones sprouting near them)
Step 1: Start with the planter
Step 2: The Dirty Work
Plant your seeds in it now, or locate some herb sproutlings, very carefully dig them up, being careful of the root, and put them in your planter. Now put some more dirt over the roots of the plants, until just a little below the top of your planter.