When Jesús Carmona was here he recommended that every student of flamenco improvise a little bit each day. In honor of that, here's a guided exercise in improvisation along with a video and examples of how a letra can vary.
First, the letra:
In the video example the singer interprets the same bulerías letra in two different ways, which makes it great to practice to.
Version One (5 minutes in)
Dime niña hermosa
quién te peina el pelo
RESPIRO (one compás break, 12 beats)
lo peina un estudiante
te lo riza un artillerooooo... de la artillería
que con gracia y salero
con gracia y salero