Mason jars - preferably wide mouth
Rocks/pebbles/marbles - something for the bottom
Fill the bottom of your jars with 1 1/2" of rocks then fill the rest of the jar up with soil. Put just a couple seeds in each jar about 1/4" under the soil. Decorate your jars with tags, plant markers, twine and set in your windowsill.
I used twine and chalk gift tags I found at target. Instead of writing with chalk I used a white marker.