Use units to defend buildings

This first tip might be obvious but just in case: Make sure you have your military units spread out around your city to help defend from invasions.

New units can be placed in your inventory

Crowded for space? Newly minted military units can be dropped into inventory rather than being placed. Just hit‘cancel’on the bottom right of the screen to do so. Be aware that units once placed on the field cannot be put into inventory.

Farm chart cheat

Use this chart to determine the optimal crops for you to plant based on your routine of playing. Also note that while the lifespan of crops are longer than other Zynga games, they still do wither.

Selecting targets in battle

In battle, destroy enemy units that have an advantage in attacking unit types that you have first.

So for example:

Tanks = Good against Soldiers, Subs, and Fighters
Artillery = Good against Tank, Battleship, and Bombers
Soldiers = Good against Artillery, Aircraft Carriers, and Helicopters

If in one battle you are fighting against 2 Soldiers & 2 Artillery

You should fight with:
3 Tanks (good against Soldiers)
2 Soldiers (good against Artillery)

Now look back – they have soldiers (good against Artillery WHICH YOU DO NOT HAVE –so ignore them at first) – But they do have Artillery, which are good against TANKS.
Therefore, use your soldiers and try to defeat the Artillery units first – hopefully before any of your tanks are destroyed. After that they will only have soldiers left – which can still do damage to you, but not as much.

More information about Empires & Allies click here