Upon graduating from law school, he joined Houston's Fulbright & Jaworski law firm, where he later became partner in 1986. Miller remained at this law firm until his appointment to the district court.
After earning his law degree, he joined Houston's Fulbright & Jaworski law practice, and eventually rose to become a key figure there in 1986. Miller continued working at this law firm until he was appointed to the district court.