ABC Plus
My primary tool for creating musical scores in PDF format is the ABC Plus notation, in particular the package called abcm2ps. By using it as a starting point, I not only get printable output, but PDFs that work nicely with the AutoSongbook application. As a bonus, the same source files can be used to generate MIDI for other musical purposes.
Although there are graphical tools for dealing with ABC files, I tend toward a more basic approach. Using the Emacs text editor in combination with a plug-in that understands ABC syntax gives detailed control over page layout.
The final piece of the software puzzle for creating scores is something to convert Postscript -- which the above plugin generates -- into PDF files. Ghostscript does the job nicely as well as providing previews of the graphical output.
Before creating AutoSongbook I would do whatever was necessary to force an entire song onto two pages. Page turning while playing guitar is a skill I've never mastered...and don't intend to attempt. Being able to format my songs so that they're at their best for readability without worrying about a page count has been one of the advantages of AutoSongbook that I hadn't fully considered when I started work on it.
Parameters
I'm currently in the process of determining a best set of formatting parameters to use when preparing a song for use with AutoSongbook. The following represent my preferences at the moment:
pageheight 14.0in pagewidth 8.5in musicspace 0.4in vocalspace 0.4in textspace 0.4cm titlespace 0.0cm topspace 0.0cm topmargin 0.0in botmargin 0.0in leftmargin 0.4in rightmargin 0.4in composerspace 0.15cm maxshrink 0.0 notespacingfactor 1.0 gchordfont Palatino-Bold 13.0 composerfont Times-Italic 10.0 historyfont Times-Roman 10.0 textfont Times-Roman 14.0 vocalfont Times-Bold 14.0 titlefont Times-Bold 10.0
These can be copied into a format file that is used by default whenever an ABC song is converted to Postscript. In addition, I modify the 'scale' parameter inside each song file so that pages are as full as possible; it makes setting the song's duration in AutoSongbook easier and more accurate.