[Benjammer]

I'm not really an authority on expert implementations consulting, but off the top of my head:

>tools

A notebook. An excel/sheets spreadsheet. An open mind. People skills. A sense of humor.

>processes

Regular check-ins with stakeholders. Actually having a well-structured, end-to-end implementation plan at some point for any given client. Being willing to dramatically shift said plan on a dime in order to keep everyone happy and maintain the business relationship.

You can also work for a few years and then get a job at whatever client company you liked working with the most, pretty easily. I've seen that happen a lot.