In this video Skippy Blair counts the sets of 8 in a piece of music. The hand motion she uses is a good exercise when you count music to work on timing and training your body to hear the sets of 8.
Listen for the heavy measure, beats 1 to 4, and the light measure, beats 5 to 8. The light measure is the thematic “conclusion” to a set of 8. Listening for the thematic conclusion is a good way to identify a set of 8. All dance music, except the waltz, is structured in sets of 8. The waltz is counted in sets of 6.
From Skippy Blair’s 2006 Summer Intensive, video courtesy of Skippy Blair