Tomato Dirt recommends to gently grasp the base of the sucker between the thumb and forefinger and pinch or wiggle the sucker until it cleanly snaps to remove it. On young plants, using fingers is recommended to encourage plant wounds to heal faster and to decrease risk of disease.
Older plants are tougher and may require the use of a blade or clippers. Disinfection of the garden tool is recommended following pruning. Pinching suckers is likely to produce larger fruit, as the stem no longer needs to send additional energy and resources to new branches; however, pinching suckers also reduces overall production of fruit.