What custom skills have you introduced and for what reasons? I'm thinking about adding a Proffesion/Trade (as in job) (...) skill to measure how good someone is at, for example, cooking or singing etc. And before you say that it all can be done narratively (I love how broad this term is) - no, sometimes it can't. Sometimes there is a contest of skills, sometimes a PC actually wants to measure their mastery of something other than shooting or piloting.
Thanks in advance for suggestions and ideas!