1. Find someone who knows marketing writing, not a manual writer, a programmer or a graphic design firm. (If you hire a design firm that provides writing, make sure that their writers are professionals with skills that demonstrate a high level of ability and experience.)
2. Find a marketing writer that knows your industry. Go even further, and see if your prospective writer can get technical and speak with your employees and product managers. Get a specialist.
3. Find a writer with EXPERIENCE. The best way is to ask for clips. Good writers/geeks should have a Web page, with links to pdfs and writing samples.
4. Determine whether the freelance writer you want to hire is truly professional. Don’t waste time on hobbyists who may or not be around when you want them in on conference calls, interviews or meetings.
5. Get a marketing writer with good people skills. Even if they’re not going to be working on site, people skills count. Oftentimes, individual writing projects turn into larger projects which require project management skills and team-oriented organization.