I think it depends on what you find fun and what kinds of additional rewards you'd want to get while farming. For example, Vet Maelstrom Arena throws mobs at you endlessly, so if you want to do a solo grind that doesn't involve the possibility of other people messing you up and also get loot from the chests at the end of each round, then that would work. CP is just xp for vet players, so wearing all Training gear and using Pjici Ambrosia potions would speed things up too.

You could also farm the Imperial City and get Tel Var stones and trophy room drops, though you'd have to contend with the PVP element there.

You could go to one of the delves or other spots in Cyrodil or one of the Cadwell's Gold cp160 zones to farm mobs, I guess. Though I think this has the least secondary reward potential.

You could also endlessly cue for random dungeons and run those all day long.

You could PvP all day long, as that grants xp too when capturing keeps, etc.

My advice, do what's fun for you and don't worry about "grinding." It's a game after all. Don't make it a job.

Also, remember now that once you reach CP160, you have at least 10 zones that you can grind mobs in or do quests in for CPs.

Do the DB dailies. I am getting 75K per quest. You can even farm the bosses for a good chunk as well.

I even see people grabbing groups of the Minotaurs they give 3K-3.5K per kill.

Doing the daily dungeons as well give you about 1 champion point a run. If you Q for the random its like 250K xp right there, not including the xp from the run itself.

I am right around 400. But I gain 25 in a week just doing the dailies and not playing for very long.