You could consider the FME Workbench to be a graphical IDE (integrated development environment). Therefore it makes sense to employ the concept of Design Patterns to FME Workspaces. For anyone that has worked in an object-oriented language (like Magik) Design Patterns are not a foreign concept.
There is a presentation on FMEpedia called Introduction to Design Patterns that is worth reading by anyone wanting to make more efficient use of their FME Workspaces. The included PowerPoint presentation has a number of design patterns. Note that this presentation was inspired by a discussion the FME people had with someone from the Smallworld community and the examples in the presentation are all Smallworld-FME ones.