Three most important points for enterprise architecture process success (IMO).
1) Proven and existing methodology. EA is quit complex path to follow without proven methodology to follow you might well be doomed to fail. There are proven methodologies such as TOFAF, DoDAF, Zachman, etc. you should choose the one that closest to your field, adapt it to your enterprise needs and use it. I heard about guys that try to create their own methodology, but they all realized in one point or another that they are on the wrong path.
2) EA Champion. EA process involved with a lot of enterprise politics. You need someone form the enterprise that he’s well respected by his colleague and the CxOs. Someone that will help to spread the EA process across the enterprise, to open the right doors and to resolve conflicts.
3) Team work. EA is team work by nature. You need to share as many people as possible in the process in any cycle of the process practitioners. The core process management should be made by group of people. There should be a coach, but not a manager. It should be group work. This idea should be imposed on any task that made as part of the process. Each of those task groups should contain representatives from groups in the enterprise that could be affected by the group work.