If you are in the castle and want to start moving on the next turn, garrison all the slow units, so that hero has only the fastest unit(s).The slower that unit is, the less distance your hero can travel per day. Distance your hero can travel per day depends on speed of the slowest unit in his army.So, the most important thing is: BALANCE BETWEEN TROOPS AND STRUCTURES.Watch your gold - always keep enough spare gold to recruit about 70% of creatures in your castle or you might end up with well-built castle but no money to recruit troops when enemy comes.Build all creature structures you can before upgrading them - this way you'll end up with more troops to recruit.
If you're warlock, be quick to build dungeon. Hints and Tips for Heroes of Might and Magic 2
