"For most people who engage in erotic tickling, the pleasure is often a byproduct of the interplay of physical and psychological elements," says Dr. Nazanin Moali, a sex therapist and the host of the (opens in a new tab).

Source: https://mashable.com/article/tickling-fetish-explainer

"Start with caressing your face and neck, then move towards your belly using gentle stimulation," Moali says.

Source: https://mashable.com/article/nipple-orgasms-guide