azurekenshin: Any extra general tips will always be welcome.
The single most useful skill for any hero is Logistics. The other must-have-except-on-tiny-maps for primary hero is Wisdom. Estates is surprisingly useful for secondary hero, but your primary one is usually better off picking something more useful.
This might be obvious, but usually build all structures before upgrading them. Except in cases where the upgraded unit has an extremely useful skill. Also, be aware that upgrading a unit costs double the difference in gold.
Again, not sure if you know this, but the distance your hero can travel depends on the speed of slowest unit in his army. Giving a single peasant to your secondary hero is not a good idea. Pay a little more and give him something with a decent speed. But then again, don't waste the most powerful unit on him, even if it is fastest.
For the same reason, it might be a good idea to put slow and strong units on town defense duty.
And for the same reason. If you end your day in a castle, move all but the fastest unit to the castle garrison, and then move them back to the hero the following day.