Some ideas:

• as far as generic tools you didn't list -- pack and unpack are extremely powerful. You might already know them, but worth mentioning.
• learn to use templates (Template::Toolkit is a good one).
• try writing your own module, with unit tests -- use http://www.perlmonks.org/index.pl?node_id=158999 as a guide.
• What's this Moose thing all about?
• Read some of the Meditaions (example: reading and modifying bitmaps in pure perl)
• stop writing perl scripts, start writing perl programs.