I do this:

Automanagement.
I dont train low morale soldiers i.e. Town Watch. If the machine does, I disband.
Try to steal Roman lands being one.
Dont use ships, only if necesary.
I dont use cheats.
The enemy will resist the siege as long as they can.
I will use my hoplites to hold the enemies, not allowing them to come into my settlement.
If I use onagers, I will burn them!

Cheers