Posted April 22, 2013
Income includes one offs like quest rewards but the main source is buildings in the capital & provinces. The capital buildings should all be built with emphasise on trade after the first unit type. Example I build the capital sharmans building first & just mass produce them until all my inns/ market places are finished... any building which adds to your income will have it marked in the reference when you right click on it.
Initially, I used to rely more heavily on province and capital income but - depending on hero level - defeating strong sites can be extremely lucrative. Also, by fighting regularly you will also have surplus cash to keep building even the more expensive buildings (you normally won't have all resources so many buildings will be quite costly!) and hence afford even more buildings.
Picking the right fights (and winning them with nil/low losses) basically accelerates the entire process of building up the economy and your hero skills!