There was once a Mass in our university (Sunday dorm mass; our university has on-campus accommodations) where everything went wrong
It started with the entrance. Readers process together with us servers, and when we get to the front of the altar, they form a line with us (Father at the center) and bow with us and Father. That time, I didn’t know they were all new readers who didn’t know how our processionals went, so I didn’t bother telling them.
First mistake: the reader I was processing with walked so fast. I tried to slow down as I was carrying the small bell which I rung to signal the beginning of mass (it would ring if I started walking fast), but eventually I had to keep pace with the reader so as not to break formation. To my horror, the bell started to ring and I had to twist my wrist so that the part with the chimes would point upwards and the bell wouldn’t ring anymore. Of course, there was the ringing sound again but after that, at least the bell wouldn’t ring anymore.
Next: the readers were about to go to their seat after reaching the altar, leaving only me to bow together with Father

I was so embarrassed; luckily they realized and went back to bow with me and Father
After that, me and my fellow altar server were so rattled that we forgot to put the chalice before handing the bread and cruet and other errors which I now forget

