I wasnt big on it at first but after playing a few Japanese games that its main focus was hypnosis and transformations I would say;

Character is hypnotised and has their clothes altered like tight bodysuit or cyber-wear and has a visor covering their eyes feeding them more hypnosis or instructions and having characters personality altered either fully or partially. It will also enhance their abilities like strength, perception or speed but their will will always be limited and controlled.

A favourite is Mission Mermaiden for that stuff

I like rare stuff like hypnotic gases, hypnotic viruses, hypnotic dance of hypnotic unusual body parts (like feet)

Eyes and pendulums NO question. Just them giving in to such simple things. Pleasured and obedient.

either tech control or biological agents. love the sense of contact. visors, implants, slime, bugs, all that. spontenaity and unavoidability also appeals to me. i'm a sucker for 'hey, i was just watching something on my tv/phone/computer/whatever and suddenly The Big Hypnotist Appears'
something i'm also big into is hiveminds. becoming a smaller part of a whole. like i've had elaborate fantasies about being abducted and transformed and conditioned into becoming a worker bee alien thing, or whatever.

i'm with the tech control gang but in a overly specific way... i like tech devices that hijack the nervous system to take control of the voluntary motor functions (bodycontrol).
This kind of devices usually include a collar, a microchip (specifically placed on the nape, to make contact with the central nervous system), also it could be an small antenna in the top of the head which intercepts the nerve impulses and interchanges them with remotely received commands.
Others could also include implants, like in the back alongside the spine or in the limbs to stimulate muscle movement sending electrical impulses to mimic the ones that occur naturally in the body to take control over the body leaving the mind intact.

I came back to read this thread, it's a good catalog of ideas that I need to search to bring here at the hub. Good stuff that you like!