[Catalyst] How to use self made Template Toolkit plugins?

[kakimoto at tpg.com.au]

hi there
 i am thinking of writing some template toolkit plugins for use within
my *.tt2 files.

I read the Template toolkit book but of course, this is catalyst so some
things (ie configuration) is different

1) how do I tell my *.tt2 file that a certain template is to be found in
a certain location?

2) where is the best place (based on best practices) to store the plugin
files for TT2?

thanks

k.akimoto