Key Principle: Make a searching and fearless written moral inventory of yourself.
Step four is the one a lot of people get stuck on, and now I understand why. It is so overwhelming to try to think of every event, person, situation, anything that elicits a negative emotional reaction1 - over your entire life. I wasn't even sure where to start.
I went with the brainstorm method at first - just wrote down everything I could think of off the top of my head. Then I divided my life into segments (pre-kindergarten, elementary school, high school, etc.) and brainstormed with that period of my life in mind. I went through my contacts and photos to spark additional memories. Then I went through a list of negative emotions and wrote down any other memories that came to mind. After I felt like I had a good list (~475 items), I copied it into a spreadsheet. Then I filled out additional columns explaining why each inventory item sparked each negative emotion and what character weaknesses led to me feeling that emotion.
Once I got halfway down the list, I started noticing patterns. It was actually kind of fascinating seeing them. I am very insecure. I compare myself to others, which results in a lot of jealousy and resentment. I want to control everything, which results in frustration when things don't go my way. I have a lot of anxiety about getting in trouble and being punished. I'm more materialistic than I thought.
After finishing my spreadsheet, I made a list of every negative character trait I had used frequently and then searched through the spreadsheet to find trends and patterns. I hate being late and have very low tolerance for other people being late. Those kinds of inventory items are caused by impatience. I'm also impatient with kids, pets, long car trips, trips that take longer than they should, slow drivers, and processes that take a long time. I summarized my findings in a moral inventory essay.
I really had no idea how much of a pride problem I have. After working on this list it was extremely easy to pray, "I am so incredibly flawed and broken. There's no way I can fix myself. Please bless me with grace to overcome these issues!"
1 The ARP guide says to list positive reactions as well, but the other 12-step programs I've looked at have only focused on negatives. Seeing how long it's taken me to analyze the negatives, I decided determining my positive character traits can be a future project.