The title might need some explaining: ideas you had for use in a hypnosis story/caption/roleplay that was odd... but you feel might merit further discussion.

Example:

So... While thinking of ideas for a Fairy Tail hypno harem story, I had an odd idea: the hypnotist makes the girls wear their hair certain ways while hypnotized, as a sort of symbolic demonstration of control; then has the girls associate the hairstyle with pleasure and obedience...
For instance, making Lucy style her hair in childish looking pigtails. Mirajane a braided ponytail. Erza in oxhorns. Etc.
With it reaching the point where, even when not hypnotized, the girls can't masturbate unless they have their hair in that exact style.

Odd idea, right?

Personally, I never had an idea in my life. But when it comes to creative hypno-stuff, pretty much everything Sleepymaid does comes to mind.

Eh, while I love Sleepymaid's stuff, the most creative idea I've seen from Sleepymaid is the Hypno-Squid.

Which was super creative, don't get me wrong.

...Now I really wish Squid Ops hadn't been cancelled...

I remember Squid Ops!

It was a super interesting concept, but from the way that Sleepymaid felt like they had to make multiple versions, I'm guessing that they were a bit too hasty.

It's just conjecture, but I suspect Sleepymaid probably jumped into drawing and coloring the comic without a particular plot ending in mind or a way to get there, so when they inevitably ran out of story beats to keep things moving, they had to restart it.

Squid Ops sure had a ton of good concepts though. I always liked the sequence with the priestess. That, and Mui flagrantly using her new pet squid every which way, consequences be damned!

Whatever the real reason was, it's shame they decided to cancel it.

DON'T MAKE THE SAME STORIES. :^)))))

"Honey", "Milk", "Leche del Diablo"... The new drug craze, which dodges the whole DEA alphabet soup by falling under some crazy FDA alphabet soup, which are, quite frankly, a slap on the wrist.

Because chemically, they're just human fluids. Even though they're really incubi/succubi fluids. Of course, there's no way there isn't a more sinister goal there than just making money...

The perfect case for a dimensionally displaced troubled elven priestess with a holy sword and a personal experience with succubi to tackle with the help of a local hacker.

Today, I saw a character with a symbol in eyes, that wasn't a heart nor a reflection of a pendulum or other hypno tool.
Despite being pink, I thought it may be a diamond or club.

This lead to a stupid idea of hypno girls fighting depending on the faction they belong to: clubs (♣), diamonds (♦), hearts (♥), or spades (♠) in the eyes.

You mean like when Chrome got mind controlled by Daemon Spade in Hometutor Hitman Reborn?

Sorry, don't know the anime, can't be sure. But are there really at least 2 factions of mind-controlled, recognizable by the different symbol in the eyes, in your story.
It's probably a little different, especially since it should be a "common" anime, not something for hypnofetishists :p

Concept: Somebody attempts to hypnotise a split-brain patient, but it only works on one half of them. The other is unaffected.

Alternatively, one half of the brain uses hypnosis to dominate the other (in essence, having the dom and sub share a body).

I'll admit, the concept doesn't appeal to me personally, but there might be someone here that finds it interesting.

Your alternative reminds me of Psychonauts 2's Cassi 'O Pia

Wholly unintentional, I assure you.

Actually, here is one rather strange idea I've had in the past:

A hypnotist takes control of a group of large breasted women, but instead addresses all the commands as though they were directed at their boobs. Things like: "Your breasts feel so uncomfortable, you should take off your bra", "You breasts desperately wish to be seen, take off your top", or "Your breasts feel sensitive and needy, they want me to play with them".

I don't know, I was partially inspired by this EMCSA tale:
mcstories.com/PussyControl/index.html

I recently saw an ad for a "50ies special menu" at McDonald's and got a weird idea:

A girl is curious what that special is about and orders it. As soon as she does, two robot arms grab her and take hold, pulling the surprised girl into another room where she gets stepfordized.

The end is that girl happily serving a menu to her beloved husband (the next customer in line who ordered the menu).

Question: Can females also become 'husbands'?