[mobilene]

I'm a Director of Software Engineering today, but early in my career I was a technical writer.

The #1 most important thing imho is know your audience. Who are you writing for? What do you know about them, or what can you reasonably successfully guess about them?

I once wrote a suite of manuals (yes, I'm that old) for an ERP software product. The audience was people on manufacturing shop floors, AP and AR people, sales people -- in other words, people who didn't know and didn't care about the underlying tech. They just wanted instructions to do their tasks. I learned their lingo and used it, and otherwise tried to write on a fourth-grade level.

At another company we wrote documentation that techs at wireline telephone companies used to install and operate our software. While these people weren't software developers, they were technical people and I wrote to them as such. I gave them the theory and concept behind things as well as the task instructions they needed.