Speak to parties directly and early on files. Become someone they know. Treat everyone you mediate for, and everyone you meet (parties, lawyers, translators, assistants, receptionists etc.) with respect. They all matter.
Find a niche. Build it (even if it is one that found you, rather than one you sought).
Be interesting. Be interested.
Do things other mediators don’t usually do (or do well):
Hold pre-mediation conferences to pin down the administrative logistics at least several weeks before the mediation.
Don’t give up easily. Try everything you can (e.g. blind offers) before you usher them out the door without a resolution. Even mediations that don’t settle can lead to referrals if you leave no stone unturned along the way.
Follow up with them as appropriate in given cases to see how things are going. Show that you are invested in their success.
Be creative. If most mediators don’t brainstorm options (as they don’t in the commercial world), do brainstorm new ideas and approaches.
Let it be their ultimate decision.
Show empathy for the people, as well as an understanding of the issue.
Speak their language (e.g. if it is an engineering issue, become familiar in advance with the terminology and what it means).
Use questions to educate rather than opinions to persuade/push.