How to successfully utilize your "Dominion Wall"?

[Saxon]

Whoever is ahead in dominion is also going to win more battles and, depending on scales, be racking up other assorted bonuses. It always seems like a small thing, but the extra production or magic or morale on every province or unit adds up. Then, once the higher levels are reached, there are various globals which are directly tide to dominion. If I am just a couple of % ahead of you each turn, by the end of 40 turns I have a big lead.