I like using my mundane troops. Right now, my melee champions don't feel awesome so I'm glad that I love to use mundane troops as one of my focus. Not meant to be "How to beat the game in 40 turns or less" (I'm too casual for such testing), my units are quite normal.

I like to start using peons initially, until I get access to spears. Which means that if I start with the proper technology, I start using default spearmen from the beginning. Once I have some mass in the city, and considering the future campaigns, I'll go for custom spearmen. Depending on my actual research, it can go like this:

Basic Battle Maiden: Basic spear, Bloodthirsty, Charge and Fast. For the long run, have her upgradeable in every armour and weapon slot. That will allow her to keep up to date in the late game with the benefits of many levels from the early game. May end using cold or lighting spears, and cloaks against fire. Will miss stuff like rings or amulets. It's role is to close in as fast as possible to the enemy (including the archers if not well positioned and small enough map) and deal as much damage as they can. Ignoring the 66% of the enemy armour is never a joke and unlike other weapons, spears don't require iron or crystal (basic spears, that is) and can be adquired in research faster than the other more powerful weapons. These early Battle Maidens end as city guardians if they are part of a Party. They work in Parties or better.

Battle Maiden: Like the basic Battle Maiden in all aspects but with the whole leather suit (pic has boar spear, disregard that detail). I usually try to start with this instead of the basic version but it depends. Not intended to stay at home to defend cities. They work only in Groups or better.

Knight Maiden: Basically a mounted Battle Maiden. The horse allows to avoid being prone and gives more base movement so the army can move more in the strategic map (good to reinforce armies in the vanguard too), at least until archers are added to the regular rooster of the army. They work only in Groups or better.

Wasp Maiden: Up to 0.85, I didn't feel like there was a need for archers but since 0.85, they have become a must have for the armies. I try to completely avoid the default ones and go for custom ones. My archers must avoid armours due to cost and possible initiative penalties (they should avoid melee and against enemy archers, I hope to hit them first with my own). I don't like them to burden me with unnecesary crystal costs neither, so no rings or stuff like that. So they just use a bow (upgradable), bloodthirsty, fast and some accuracy boost. As I research more things, they get to upgrade only their bow which is fine for their role of basic archers of my army. Default unit to build as defender of cities (defeault spearmen would be the other option depending on need/cost/hurry). They work only in Groups or better.

(Alternate) Wasp Maiden: This is an edit (and alternate option) for Wasp Maidens. When crystals are a solid option to use, these Wasp Maidens add robes that add +2 to initiative (strike first, strike last), boots that add dexterity and (more importantly) negate being prone and a troll charm to give some regeneration in strategic/tactical. They can upgrade their bow which should be enough to keep them doing serious damage (and in my last game the armour, which I tested and ended with plate and penatlties to initiative!!  ) They work only in Groups or better.

I haven't done it (yet) but a third alternate to the Wasp Maiden would swap the magical boots for a Warg (or horse only if wargs are not available) for negating prone status and initiative bonus (horse doesn't give this bonus). The presence of troll charm in this and the previos Wasp Maiden build is debatable but saves me mana from regeneration enchantments (that could go to Iron Skin if I pick Earth ranks or more mana for Fire Storm/Cloud Walk).

And those are basically the units that you can expect to find in my armies. My main armies will end more or less like (always armies of 7):

1 Sovereign/Champion

2-3 Battle Maidens / Knight Maidens

3-4 Wasp Maidens.

Still experimenting in the "Mages" section. By the time I get them, usually I don't have so much use for them except as reinforcements so I tend to use the default or some new experiment:

Wolf Mage: This is based on cold damage/protection (staff, ring, one amulet, cloak) that could use alternate model for fire. Unlike Wasp Maidens, they use some protection in the form of Ironskin, extra constitution and one amulet. Robes, Fast trait and Warg for extra initiative. Mage units are the only regular ones beside Champions that are not based on piercing damage. They work only in Groups or better.

I do have some auxiliary troops in the style of defenders, for example. But I usually try to focus on those units I mentioned before.