Purchased these at Home Depot - these are six inches high, but they have a variety of kinds. I use leftover paint from my dining room.
Drawers from old furniture in the basement. Make sure to drill several holes in the bottom so water can drain out.
Table legs come with screws in them - just drill a hole in each corner and screw each leg in. I put wing nuts on top to secure the legs in place.
Add dirt and herbs of your choice - enjoy!