Accessors are just a clear example.

Nowadays I use Moose for them, or if I can't then Class::Accessor.

I needed tt for a set of methods that operate on two different classes in almost the same way. It's still just boilerplate code (the object that needed this code gen was a factory object with some convenience routines).

As for macros - C preprocessor style ones, that is - you can use TT macros. See Template::Manual::Directives.