A friend told my Mom how to do this, she has been using this method for several years.
You will need:
Yarn (I am using cheap acrylic Red Heart brand)
A drip try for flower pots
Step 1: Braid Yarn & Insert Into Pot
Cut six strands of yarn about one foot long (you want it to reach from the dirt line to about 3-5 inches hanging out of the pot, depending on the size of the pot), tie a knot on one end, braid, and tie off the other end. Poke one end through the hole in the pot, and pull out a few inches.
There's no measurements here, since you can do this for any size/height pot you would like.
Step 2: Get Dirty
Fill pot part way with dirt, place plant in center of the pot, and fill the rest of the way covering the roots (or seedling starter in my case).
Step 3: Water It
Place pot into your drip tray, fill with water, and let that baby water itself.