Step 1: Getting Everything Lined Up
The idea here is just to do a quick layout to make sure everything fits.
I started by turning the soda bottles upside down and seeing about how much I wanted them to stick out. This is partially due to the size of the roots you will be working with but also partially aesthetics. Commit, and cut them all the same size.
Once you have the bottoms cut off, turn them upside down and draw a sketch around the bottles onto the lid. This will give you the sketch of where to cut your holes.
Step 2: Making the Cuts
Cut out the pattern you created in the last step and use your poker tool or blade to cut holes in the top (bottom?) 2 inches or so near the soda cap. It will not hurt to do this as high as the spot where it touches the lid, but is unnecessary. These holes are just for wicking the water up. If your soil is not wicking up the water, you may wish to add more holes later.
Step 3: Put It All Together
Fill with about 2-3 inches of water in the reservoir. CAUTION: Do not overfill. The water you put in the reservoir will be mimicked in the bottles so you only want to put enough water in it to wick, not to saturate. If your roots are constantly sitting in unaerated water, they will rot and the plants will die.
Use a potting mix, not soil, for the pop bottles. Potting mix has better wicking ability than top soil. Top soil may not work at all in these systems and also invites unhealthy bacteria that are unanswered in an indoor environment.
AESTHETICS: I will end up painting this tomorrow, before filling it up with water and potting mix. This container is not rated for outdoor use but if it were, a clear container outside would invite algae and rob the plants of nutrients. I will be painting simply because my wife will not be happy with a plastic box sitting on the cabinet unless it is aesthetically pleasing..