Just emphasizing this. Never overlook the easy to cast buffs and leaving your stack permanently buffed if you can handle the upkeep. Another good technique is using a decently strong summoned unit to add to your early exploration and resource grabbing. When no longer needed you can kill the unit off. And finally, take utmost advantage of any benefit the units of your faction have. If you roll around with a lot of ranged units, use slow, binding, fumes, etc on your enemies. Conversely, if you roll around with heavy melee troops of destruction, haste yourself, blind your opponent, etc.
As you learn the units/spells/skills, you’ll understand the combos that become available. Take advantage of as many as you can.