"Beautiful," in referring to code, may be an overuse of the word. I prefer "readable." And it isn't only Perl code that can be readable. It can be any language. There are principles that apply to all making any bit of code readable and maintainable. And does it need to be maintained by you or others (though the way my memory is going, they are one in the same).

Perl::Tidy is similar to other "tidying" programs, but I don't always agree with the author about what is tidy.

I'd read the thousands of links out there on coding practices, Perl and otherwise (you'll often see Perl badgered for it's tendency to be poorly written).

Then use those, plus a hybrid of what works for you and then stick to it (though I have altered certain stylistic practices once or twice in my coding career). Personally, I always try to write code that looks good on the page and that I can understand and fix months later. To write it so it is readable takes far less time than it takes to decipher poorly written code later.