There are several broad strategies that I pursue:
Page: normally 1 or many. Singleton is just to get quickly to Champion to enable a big engine & protect myself from Warrior - basically I build something to cycle quickly and then rapidly bulk out on terminal draw & payload to green. Many is where I want to pound the opponent with Warrior card kills. Even I do not kill the enemy Warrior(s), I find you can get huge mileage by destroying all their infrastructure and having pretty good of flipping Champion or Hero. Something like Warehouse/Smithy/Page is a one strategy while something like Chapel/Iw/Page can be a many option. Note that when playing "Many" you will leave many of your pages un-upgraded, Treasure hunter is terrible for killing the enemy and while more warriors are nice you need to be cautious about filling the deck with cards.
Peasant: 2 or higher. Normally I am either gunning for Disciple, in which case I will draw deck and a second Disciple will be huge ... or I am going for Teacher to enable a quick gain of newly non-terminal or newly - big drawing cards. In either case having that second Disciple is pretty nice. More rarely I will build a deck that gets cash from Soldier (e.g. turning Spies into Labs) and grab a few extra Peasants to help the cause. Unlike the Page line, nothing useless is gained so the only downsides are bloating the deck by a card and having a dead card when Travellers collide, which is mostly a non-issue after Soldier.
