Правильно? You must to keep of golden middle.

https://idioms.thefreedictionary.com/golden+mean

Must не употребляется с частицей to.
Golden Middle - это название российской туристической компании, а не золотая середина в Вашем контексте.

It' very interesting! Thanks a lot !

the golden mean the avoidance of extremes. ( I know).
This phrase translates the Latin phrase aurea mediocritas , which comes from the Roman poet Horace's Odеs

It's

Elena, my gratitude is limitless. )

https://www.google.com/search?sxsrf=ACYBGNQe2_KFGgHsWWcHeis_j7wjEjZO-g%3A1570896334187&source=hp&ei=zvmhXduLBo2asQW88bKgCA&q=%22keep+to+the+golden+mean%22&oq=%22keep+to+the+golden+mean%22&gs_l=psy-ab.3..33i22i29i30l3.1131.5688..5959...0.0..0.363.5990.1j11j9j6......0....1..gws-wiz.....10..0j0i131j35i362i39j35i39j0i67j0i10j0i22i30j0i22i10i30.tZwp9Iy1N7c&ved=0ahUKEwjbquTvjJflAhUNTawKHby4DIQQ4dUDCAc&uact=5

Улий, my gratitude is endless)

*Thank you - is usually enough, Zoya

You’re welcome

I'll decide personally how to displaying my gratitude. Andriolli

Suit yourself. But if you tell everyone that your gratitude is endless/limitless, you’re going to start to sound phony.

“I'll decide personally how to displaying my gratitude.”
This was written in the language of Shakespeare, Mark Twain, Jack London, and Galsworthy!!!
- just an example of the BOOMERANG, nothing personal...

Смотрите, Александр, как замечательно я реагирую: я прошу вас, Александр, чтобы исправили это мое предложение “I'll decide personally how to displaying my gratitude. Что же в нем не так?

1. Отношение/реагирование твоё - 💩 2. how to EXPRESS my gratitude.

1 очень грубо.
2 понятно.

1 👍🏼 😆 2 🙏

андриолли 1,
I could have used BOOMERANG #2 from the widely-discussed​ arsenal: "Иди и учи". However, I won't do that, I'll just satisfy your request:
I MYSELF decide how to EXPRESS my gratitude.
Please note: "how to displayING" is an illiterate phrase - you cannot use TO with -ING.
My best wishes.

+++Саша: Excellent English!

🙏

Александр, благодарю за объяснение. Я не буду использовать TO with ING.

To with -ING используется, но не с глаголами, а в определённых., устойчивых выражениях с герундием, то есть, когда -ING придаёт глагольной форме свойство существительного:
I’m used to doing this kind of work; I look forward to seeing you и др.

Спасибо.

+++Саша

Dmitri, I found an explanation:
To navigate or strike a balance between two sides, positions, or approaches to something, especially when trying to avoid one of them.

Thank you.

You're most welcome.