

Miner. The most used unit ever. Obviously. Miners are the same for both Order and Chaos, though Chaos gets the handy regeneration, which lessens the impact of early rushes (very little, lol). But what seperates a pro and an... average player? Miner optimization.

1. Prioritize gold first, since it's what you "normally" need, though it changes depend on your need of mana (usually 4-6 miners for gold until you put one on mana.) Max number recommended: 12 gold, 4 mana. (FEAR MA ECO!) But the number of miners on mana depends on your army so this isn't the "best" number, ok?
2. ENEMY ATTACKING! SEND ALL YOUR MINERS TO GARRISON! And let your eco plummet to the ground while your enemy continues to mine his. Send only the miner being attacked to garrison if the enemy is few (like 1-2 SW. If more, run! If enemy is archer? Send units back) while trying to buy Castle Archer. Enemy bombers? Keep mining. I'm serious. But split your miners out. Like one for each mine, one for mana. If the enemy aims for one specific one (based on his running direction), send out one miner from that group out and let one of them die. 150 gold (miner) = 150 gold (2 bombs) If the enemy manage to trick you and kill a large amount, then...yeah, you're screwed. The micro required to do that is high, but possible.
3. Wondering whether to buy miners or units? Simple. Map size. Small? Units. Large? Miners. Med? Depends on the pressure.

4. Walls. Order's (or turtler's) best friend. Along with archer/Castle archer, your little eco is protected from em harassment. Temporary until spear shows up. Or archers who'll kill your miner before the wall is done.

5. Hustle. One of the game-changing factors. Can help boost eco much faster than higher numbers without hustle. Recommend buying AFTER getting middle. Or peace. (as in lacking in pressure)

6. Passive Gold. Capable of giving you an edge in eco and can rival tower's income. The longer the battle, the more effective Passive Gold helps. Buy it in mid/late game. Did you know lv3 Passive Gold>Tower? (Needs clarification) And also, you don't have to upgrade it to lv3 in one go since you can always upgrade it throughout the game, when you have some gold/mana to spare.
7. Uh...Having trouble building more units? It's probably because of max pop. Send out miners who are unable to mine to their doom. Or ones that you don't need.
8. (Advance tip) MINER SHIELD! Who says miners can't be meatshield? Yeah, let a miner tank arrows for your archer by retreating your archer behind a miner. Pretty effective early game.
9. Even while fighting, buy units to cut down on waiting time between units via hot keys, and this also applies to miners. They auto-mine after 4 secs, but that's quite long in this game. Utilize the time fighting to bolster your army and economy.
That's it. Plain and simple. As for when to buy units and upgrade...Figure that out yourself. : D