The best place to check for creating "PDF embellishments" would be in the TimeSavers tools that work with FM, available at
http://www.microtype.com
Most of the TimeSavers effects are created by adding special markers in the FM files that are triggered when FM creates the PDF, so that neatly solves the problem of doing work in two programs.
Shlomo Perets from Microtype has many samples of various ways to enhance PDFs, and he has a very helpful "FrameMaker2Acrobat" mailing list too.
If you have time, you might also want to check out the free Webinar series, posted here:
http://www.adobeforums.com/webx/.59b84f94