I have been a professional writer for a long time, and I have saved a wide variety of writing samples.
Most of my work has been in technical fields, but before that I wrote educational AV scripts, study children's stories, comedy sketches, etc. Etc. This page serves as a menu into the various sections of the portfolio.
Each Industry has its own language and its own body of knowledge. I have worked in many industries, including, probably, yours.
Each type of document has its own characteristics and strengths, and for each project there is a particular doc type that is most effective (or at least most expedient). It helps if the writer has had experience with a wide range of different document types. I have.
The Tech Writer's first rule: consider your audience. I have written documents that communicated successfully with end-users, hardcore developers, managers, caancer case abstractors, loan processors, qants ... all kinds of people.
Before I wrote technical documentation, I wrote educational material -- filmstrip scripts, book talk tapes, GED workbook questions, educational software ... and sketch comedy, treasure hunts, murder mysteries, stories for children's magazines ... a lot of this was pre-Internet, but I have saved some of it.