Ask What is a broadly practiced freelance skill that still holds real value when done well?

[Brendan]

There are many basic tasks that almost every person working for themselves claims they can do very well. For example, many people say they are good at writing emails or managing schedules for busy business owners. Even though these things seem common, finding someone who actually does them with great care is quite rare these days. When a person is truly excellent at a basic task, they become very important to their clients. What is a broadly practiced freelance skill that still holds real value when done well?