Pills are usually found on the areas of clothing or linens that receive the most abrasion in day-to-day use, such as center of bed sheets, under the arms of clothes, around the collar and cuffs of a shirt, and between the thighs and on the rear of pants. Washing and storing items inside out will avoid abrasion.
Read more here:
https://www.thespruce.com/how-to-prevent-clothes-from-pilling-2146667
Photo by Susan O'Donnell