(Garou) Fetishes are rare items that tend to be Garou heirlooms. Garou do not give them away simply because X saved Y's life in a fight. Garou save each other's fuzzy rears all the time so trading a fetish for saving another garou's life would mean the end of every large battle would look like a giant swap meet. If you want your character to have a fetish, it needs to be approved by your -reg wizard during the application process.
If you've got a fetish, you should @create an appropriate item and have your character carry it around with him whenever he'd have it with him. ("Gee, is that a silver klaive you've got there? They really don't hide very well in public, do they?") You should also set an &GMINFO on the Fetish object which includes a description of how the fetish works, and mention in your own &GMINFO the DBREF of the fetish object for GM reference (see "+help gminfo" for more on this)
In-game rules on the creation of fetishes can be found here.