This is more accurate than using Attack-Ground.

If you want you to destroy an abandoned team weapon or vehicle, order your units to attack it with an Attack-Move order (default hotkey: A, grid key: Q).

It is always cheaper to reinforce squads than to buy new squads.

This can be useful when capturing team weapons, or for having low-health squads retreat automatically after capturing a point.

You can shift-click on Retreat to have units automatically retreat home after performing an action.

Be sure to shift reverse so unit won't turn around.

Mobile artillery should be shift clicked to your base too, so immediately after barrage it will move back to base. Shift click with US tank crews is also good when making them re-crew tanks as soon as the vehicle is repaired. Always shift click away from mines so units wont stay on mines after construction (engineers will have a very specific pose after constructing, making it easy to spot for enemies).

Use shift clicks after giving an order.

You can estimate where the enemy armour is in the fog of war by listening for engine sounds and looking at where bushes and fences are being torn down.

You can move the camera with the middle mouse button.

You can see if a house is manned by right clicking it with a unit, if it flashes red it is occupied.

With grid keys, R retreats selected squad(s).

With the default hotkeys, pressing T retreats selected squad(s).

Many units can shoot farther than they can see, using attack ground will let you shoot into the fog of war.

Company of heroes hotkeys