To add something else into the already excellent replies above, I'd say "read other people's code".
in reply to Software design -- The confussion of buzzwords
Pick a small module that you use and think about how you'd implement it. Then look at the source and see how they did it.
Pick someone you think is a good coder and see if they have anything published on CPAN; read their code.
Also, some methodologies may only be worth the effort in a larger project. If you want to learn, then think up a larger project you can tackle, or search http://www.sourceforge.net for a project wanting help (working with other coders will particularly help/stretch you).
At the end of the day,the most important thing is to code, and still enjoy doing it.