This simple window sill planter was a great introduction to using a hole saw as well as my first introduction to trying to care for plants. It cost around $10 for the wood and pots (enough for making two of the planters pictured) and only took an hour or so to make!

And most of that time was spent trying to figure out how to use a hole saw, which made this both a fun project and a useful skill-builder!

Step 1: Gather Materials

Step 2: Mark Out the Holes

Lay out however many pots you want to use to get a feel for how you want to distribute them. Then use a ruler / tape measure to mark the center of each pot location on the top piece of wood.

I used 4 evenly spaced holes.

Step 3: Drill the Holes

This is the toughest part: using a hole saw can be surprisingly difficult and unexpectedly dangerous. I read several guides on how to do it before trying. This was the best guide I found.

Important tips:

Drill a pilot hole first
Make sure you are using a corded drill or a very high torque cordless. It takes a ton of torque to swing a big hole saw around, and it will not work with an everyday electric screwdriver.
Make sure the drill has a large enough chuck for the hole saw. I had to get an adapter because the jaws of my drill couldn't fit the large diameter shank of the hole saw.
Never hold the drill near your face! The hole saw can easily get caught in the wood causing the drill to kick back. Always brace the saw against your hip or something secure and not easily bruised!

With those tips in mind, the actual process is fairly straightforward:

Drill a pilot hole at the center of each of your marked holes
Use the hole saw to drill out each hole. I had to frequently stop and withdraw the saw to clear the wood chips out of the hole and then proceed deeper.