Rav Wolbe (Alei Shur vol. I pg. 48) quotes the Kuzari who enlightens us to the proper way of rejoicing on Yom Tov. "Our Torah is divided between fear [of Hashem], love and simcha; bring yourself close to Hashem with all of these means. Your subjugation to Hashem on a day of fasting does not cause a greater closeness than your simcha on Shabbos and Yom Tov - as long as the simcha is with kavana and a complete heart. For just as supplications require thought and kavana, so too, simcha in the performance of His mitzvos and the study of His Torah requires thought and kavana. . . Recognize what good He has bestowed upon you [through giving you the mitzvos] for it is as if you have been invited into His residence and to dine at His table. . . and if the simcha brings one to song and dance - this is avodah and dveikus to Hashem!"
The correct manner of simchas Yom Tov can only be achieved through fully comprehending the words of the Kuzari. Fear borne out of awe from the majestic grandeur of Hashem, the love of one created in the form of Hashem toward his Father in Heaven, and simcha of one commanded with the commandments of his King are what make up the entire Torah! Simcha is the medium through which one's closeness to Hashem is given expression. When a person has a certainty in his emunas Hashem, simcha and even song and dance follow. They are a means of serving Hashem and a way toward attaining dveikus.
This description of simcha is quite distant from the way simcha is used in the vernacular. We must be extra careful on Simchas Torah not to get caught up in frivolous merriment that has nothing to do with Hashem and His mitzvos. If we would be privileged we could draw a wealth of emunah and inspiration from the dancing. A strong sense of the connection to our Creator would be aroused through our song and dance, creating an intense desire to strive toward spirituality and purity of heart. These feelings would accompany us, thereby positively influencing our avodas Hashem for an extended period of time. This is the way Torah true simcha should look!
How foolish are those that wait for days of simcha as opportunities to "let go." One must prepare for simcha precisely as he would prepare for any fundamental aspect of avodas Hashem, and it requires thought and kavana exactly like davening and fasting.