If you don't fight and stay shielded all the time, only build 1 barrack and 1 infirmary and build more manors for silver production.  But like XYZ says it really depends on you.  I used to be balanced and then I created a bank account and really started raiding, which collects a lot of food, so I destroyed all of my farms but one and added more mines as I seem to have a harder time raiding for iron in my kingdom.