Going back to one of my favorite examples, Shrek, the Big Pit is when Shrek overhears Princess Fiona and Donkey's conversation, he heads to Duloc, and gives Lord Farquad to her. Donkey even persuades Shrek to go after her, but Shrek refuses. During the Rock Bottom moment, Shrek returns to his empty swamp, isolates himself from the others, despite Donkey trying to split the swamp in half. (After all he did half the work.) Meanwhile Fiona prepares to wed Farquad.
In Click, perhaps the Big Pit moment was when Michael finds out that his father passed away, but he can't rewind to that moment because he wasn't there, so instead he rewinds to the last time he saw his father. Unfortunately, his last moments with his father weren't great because he was focused on working. When his father stops by for a visit and tries to spend time with him, Michael observes his past self denying to spend time with him, even when his father offers to show him how he did the quarter trick. Michael becomes upset when he sees his past self snap at his father and send him away. Using the remote, he rewinds over and over his father's last words, "I love you son." He presses the pause button and replies, "I love you too dad." Overcome with guilt, he asks the remote to take him to a happy place, which turns out to be his sons wedding. He gives a heartfelt toast to the his son and his bride. Moments later, while dancing with his ex wife, he overhears his daughter refer his ex wife's new husband, "Dad." and he has a heart attack, which results to a rock bottom point.
In Mean Girls, Regina George finds out the Swedish protein bars she's been eating, in fact aren't used to make her thinner, she goes on a tangent and adds her picture to the burn and turning the other plastics against her. She spreads the pages of the burn book around the school, causing chaos! Fights break out and all the students are forced to go to an assembly and apologize to each other! Worst case of all, Cady steps down as the new plastic and fesses up to her instructor that she wrote the burn book, so the B story, again, is lost.
Hopefully these examples gave you a better idea of how to craft the big pit and rock bottom moments. A huge thing to note is not to have your big pit then jump to the rock bottom point, because it's not going to run smoothly in the script. If you have any questions, feel free to reach out to me! More than happy to help!