Rope the steer. If you are the header, be prepared for a sudden change in direction from the steer as the rope lands.
Hold the rope in both hands, thumbs up, hands shoulder-width apart. Let the rope rest in the "V" between the thumb and forefinger of your secondary hand. Grasp the rope in your dominant hand, loosely enough that the slack moves freely through your grip as the steer moves, but tightly enough to maintain control.
Bring your secondary hand within 1 or 2 inches of the saddle horn. With your dominant hand, loop the rope three or more times around the horn, keeping the loops as tight as possible.
Remove your secondary hand from the rope and signal your horse to stop. Be sure to keep your dominant hand out of the loops around the saddle horn.
Brace yourself firmly in the stirrups without lifting your weight from the saddle. Apply steady pressure to the rope end with your dominant hand, but be prepared to let go instantly if your dally fails. As the steer takes the slack out of the rope, it should pull taut and stay in place. Back your horse to keep the pressure on the line and keep your dally from slipping.