With regards to tech, I've done my best to keep it simple because like magic, it is hard to GM. I ask that any technological advancements be kept within the bounds of your available resources. Bronze weapons and armour can be upgraded to iron, superior conventional weapons will be stronger and sturdier than normal ones, war horses will be armoured and more reliable in a fight etc etc. No one is going to invent a 150mm howitzer with explosive and armour piercing rounds with iron, lumber and gunpowder.

In short, keep advancements outside of resources minor and limited. Proceed with caution.