During the first day of Rosh Hashana, there is a well-established practice known as תשליך. The word itself comes from Micah 7:19, where "you will cast all their sins into the depths of the sea." What the practice entails is finding a body of running water and throwing pieces of bread into that body of water as a symbolic casting of one's sins.
What many do not realize is that this ceremony has its origins in superstitions. Rabbi Israel Drazin, in his intellectually stimulating book entitled "Maimonides: The Exceptional Mind," outlines the history of this ritual in depth. Essentially, we are dealing with a practice that emanated from ancient notions, one of them being that G-d and demons can be found near water. If you believe in G-d's omnipresence, this notion should make you stop and think for a moment. But many biblical figures thought so, whether it was Abraham who made a covenant before a well in Be'er Sheva (Genesis 21:31-32), King David's son, Adonijah, who thinks he can offer a sacrifice in front of a river and help him succeed his father as king (1 Kings 1:9), or the Psalmist (29:3, 139). Even the Talmud tells of stories such as feeding spirits to appease them (Chullin 105b) and drinking water from a river at night is bad because of the shabiri, the demons that cause blindness (Pesachim 112a).
By the time this practice was created in the Middle Ages, it makes sense why the primary theme of this practice was to bribe Satan. The Kabbalists added the practice of shaking of the ends of one's clothing to shake off the klippah, as if the act itself absolved them of any sins. This was problematic because taking the non-rationalist approach meant believing that the ceremony literally absolved one from their sins. Since superstitions such as these make people small-minded, this mentality had the potential from steering people from doing actual repentance, which is why so many rabbis opposed the practice.
This brings me to the important question of "do superstitious origins negate the ceremony's validity?" If your intention is to bribe Satan with pieces of bread, as if bits of stale bread is going to distract G-d's servant from doing his job, then I would have to say that this practice is absolutely ridiculous. Even saying מנהג אבותינ תורה הוא ("the customs of our ancestors is law [for us]") would be insufficient because customs can be overturned in Jewish law.
In spite of these non-rational origins, there can be reconciliation between the practice's history and how we perceive the practice today. Even though I believe that "tradition for tradition's sake" is as dangerous and menacing of an argument as "change for change's sake," I nevertheless enjoy Judaism for its traditions. Judaism is uniquely beautiful for the continuity it has kept over the centuries, hence its allure for me. I can perform the same practice as my Jewish ancestors did back in the Middle Ages, but I can derive a different purpose and meaning from it.
To paraphrase R. Aryeh Kaplan in his book Jewish Meditation, a mitzvah can be an action-based meditation. This insight has changed how I view mitzvot. The mitzvah is supposed to get your mind engaged and focused on G-dliness. Let's apply that concept to תשליך. When you are casting the bread into the water, what should be on your mind? That these crumbs are a metaphorical representation of my sins, and that by throwing them away, you are starting anew. There's that Jewish theme of renewal again. How about the water? In Judaism, water symbolizes life and renewal. Much like Daniel (10:4) did, we can experience G-d's revelation in front of water and contemplate the vast wonders that life has to offer. Let's try an insight with the fish, since one is supposed to find a body of water with fish. As Rabbi Isaiah Horowitz points out, just as fish have no eyelids and always have their eyes open, we should always "keep our eyes open" by constantly being attentive to G-d and His will. Even the act of being in front of a body of water can be an opportunity to realize G-d's wonder through His creations.
As you go to symbolically cast your sins in the ceremony of תשליך this year, take just one of those insights and keep it in the back of your mind throughout the experience. I guarantee it will enhance your appreciation for תשליך.