Gather your materials.
You will need:
You may want to pop your popcorn the day before you plan on making your garland so that it gets a little stale and is less prone to crumble. If you can't do that, try popping the corn early in the day, placing it in a paper or other breathable bag, and setting it outside for a few hours.
I found them in the regular fruit aisle at the store, not in the frozen section.
String or thread
I used the cotton yarn generally used for doilies. If you use regular sewing thread, consider doubling your strand for strength.
Be sure the eye of your needle is big enough for the string or thread you chose.
Beads or small things you can thread onto a string.
Cup of water - good hydration is always good :)