Make sure to wash out the yogurt containers first. I usually fill them up with water and let them soak for a day before drying and cutting.
Start making a cut from the top of the container down to the bottom and then make a hard left ( or right) and follow the rim all the way around until the bottom is completely cut off.
Then start cutting the body piece into parallel strips about 1/2" to 3/4" wide. Leave enough space to write on.
With each strip, cutting sharp wedges to create a spear like effect.