How do you go about walling up?

Now obviously I know how to create a wall, that's not the question. I'm asking r/aoe3 more if there's a particular technique/pattern you follow when walling. I often forget about it until it's too late, or become too paralyzed by the fear of an enemy finding and picking off my vill to start putting a wall up in the first place. Often I run into opponents with 3+ layers of walls, sometimes more, which makes it a real pain in the ass to get to their economy unless you use a bullshit strategy like oprichnik boxing or daimyo samurai spam.

Is there a specific time into the battle you typically send a vill to wall up? Do you send more than one? Do you wait a while before adding layers, or do multiple all at once?

(for reference, I chiefly play 2v2/3v3 because I can't currently think quickly enough for 1v1s)