The single most important skill
Ten-step bug report.
Every technician has to be fluent in one thing above all others.
Investigation half: structure · reproduce · isolate · generalize · compare.
Writing half: summarize · condense · disambiguate · neutralize · review.
Grammar and spelling count. A poorly written report can render a technically correct one ridiculous.
See /resources/qa-library/bug-reporting-process for the full checklist.