Getting comfortable reading stack traces instead of copying the last error line

When a Python script crashes, I still have the bad habit of reading only the final exception line. Yesterday it said `KeyError: 'email'`, so I added a default value, but the real problem was an earlier function passing the wrong dictionary into the formatter. Following the call frames upward made that obvious. Does anyone have a good repeatable method for reading tracebacks—where to start, what to ignore, and how to identify the first line that's actually mine?