This was the same problem I ran into once upon a time. What I ended up doing was writing modules strictly for myself (that is, not for upload to CPAN) that were little shortcuts for things. Anything that I found myself doing with any regularity at all, I wrote as part of my series of "Kurt" modules. Writing several of these was sort of like grist for the mill. It got me thinking in module writing mode, and then from time to time, an idea for something new would pop up, which would lead to a module that was eventually uploaded to CPAN. You can, I think, apply the same rule to writing perl modules that you are supposed to apply to writing fiction: write about what you know. Write a few simple modules strictly for yourself, and then when the Perl Muse decides to perch upon your shoulder, just sort of run with it from there.
I wrote my first module just as a collection of quick utilities that I found myself needing a lot. Getting a datestamp in a particular format, converting IP addresses between an xxx.xxx.xxx.xxx string format and a numeric format, that sort of thing. It made great practice for when I started building a set of modules for other folks in development group to use.