Speaking only for myself, I do all my own drawings, and computer drafting skills are always something we ask about when we interview. I work from schematics and illustrations provided by the inventors and sometimes make use of royalty-free clip art if it can be adapted. I mostly use vector art illustration software and, when necessary, 3D modeling software. I do a lot of tracing, sometimes from photographs that I will stage if I need a particular angle of a device or showing its use. 90% of patent drawings can be done in something as simple as Word or PowerPoint. If we ever needed a drawing or schematic that was beyond the skills of myself and our other legal department folks, we would probably farm it out to a professional illustration service.
A good resource for your friend would be the USPTO's
Guide for Preparation of Patent Drawings, last published in June 2002. Learning how to do patent drawings well is something of an art in itself and requires throwing away a lot of what an illustrator already knows about illustration, since the tools of color and scale shading are no longer available. Spaced-line shading is a fairly difficult drawing technique to master, and stippling shading is among the most advanced and sophisticated (even the state-of-the-art computer plugins can't do stippling satisfactorily). For the sake of international portability, it's always best to plan drawings from the beginning to conform to both USPTO and PCT standards.
