Lawn bowling balls are asymmetrically shaped with a grooved side that is smaller than the opposite side. This allows the ball to roll in a curved arc toward the jack in the direction of the smaller side of the ball. Smart bowlers can use this to their advantage--the curve can be used tactically to maneuver around other balls on the playing field.
A proper grip on a lawn bowling ball should be comfortable for the bowler. In addition, a grip that transfers the weight through the center of gravity of the ball will be the most efficient. This can be accomplished by making sure that the middle finger is the last one to leave the ball during the throw.
There are three grips most commonly used by bowlers, each with their own benefits. The fingertip grip involves gripping the ball with the fingertips and provides better touch for fast greens. The claw grip involves a wide spread of the fingers, and pressure being placed between the fingers and thumb. This is better for slow greens that require more power. The cradle grip allows the ball to rest with its weight in the palm of the hand and provides extra support for players with small or weak hands.
Bowlers should make sure to let gravity work for them when delivering a ball. While it will take some muscle usage to throw the ball, the ideal throw will feature a pendulum-like swing and release that stays on the same delivery line as the bowler's target. Attempting to "overthrow" the ball can pull the swing offline, resulting in an off-target throw.
Most bowlers will use a one-step approach when throwing, with the leg opposite their throwing arm stepping forward as soon as the arm passes through vertical during the backswing. Typically, the knee of the back leg will drop down during the approach, so that the bowler ends up crouched close to the ground and releases the ball when it is parallel with the toe of the front foot.