Strumstick Tuning

Easy Tuning including an online tuner (below videos)

Some Videos with notes to tune to. Further below are a link to an online tuner plus video instructions for electronic tuner use. Also, tuning the Strumstick with itself .

An Online Tuner (there are many) Here is a decent one: Tuner Ninja

2. Tuning with Electronic Tuners

Electronic tuners are easy and fast, and widely available. We have a good tuner available (see Tuner) You play a string, the display indicates what note it is, and a meter shows you if it is too high (sharp), too low (flat) or right on. As you adjust the string, the display changes to show you what is happening.
Using Electronic Tuner with D Strumstick (video)
Using Electronic Tuner with G Strumstick (video)

There are also many tuning apps for smartphones, most work similarly to an electronic tuner.

Notes to Tune To:

3. Tuning the Strumstick with Itself

Tuning the Strumstick with itself is easy, it just requires a little patience and learning what to do. In fact, reading about how to tune takes longer than actually tuning.

If you have an outside reference like a guitar or piano, the notes that the strings should be tuned to are listed above.

The strings are numbered, left to right, "3", "2", "1" , string 1 is the thinnest (the bottom one, closest to the ground) and string 3 is the thickest (the top one). The frets (the metal pieces on the fingerboard) are numbered 0, 1, 2, 3, 4, etc., with 0 being the fret at the top, which the strings rest on.

Follow these instructions:

Step 1: Finger the third string at the 4th fret, and pluck that string with the pick. That sound is the note the second string should be. 

Step 2: Pluck the second (middle) string open(open = no left hand fingers), and listen to it. If it sounds like a different note than the third string 4th fret, it is out of tunewith the third string. Adjust the second string’s tuning key until the second string opensounds the same note as third string 4th fret. Now the second string is in tunewith the third string. It may take several tests, and several adjustments to get it right.

Step 3: Now finger the second string at the 3rd fret. That is the note the first string openshould be.

Step 4:Adjust the first string tuning key until first string opensounds like second string 3rd fret. You are done!

The key trick to tuningis listening!
Pluck the note you are fretting...
listento it.
Pluck the string you are adjusting and adjust... 
listento it change. 
Tuning is not done by thinking or knowing, it's done by listening.

Always listen to the note change when you twist the tuning key. If you listen, you can tune.If you can hear a note is out of tune, you’ll be able to bring it back in tune. If you can't hear that a note is out of tune, it isn't!