Take your time when deciding who to attack. There is no time limit when selecting an opponent. Examine the type and number of troops they have, and if they are any active traps. Avoid opponents that are using traps. When attacking, use your hero wisely. Place them where they are most useful. For example, a long range mage type hero such as Calista should be kept behind the squires to attack enemies with her spells. Keep your troop formation as compact as possible, placing your melee units in the front and ranged units behind them. Make the enemy hero and long range troops your primary targets, then take out their melee troops afterwards. Give preference to easy to defeat opponents to earn as many medals as possible. This is best accomplished by attacks multiple weak targets instead of fewer attacks on stronger opponents. Use the training waiting time to judge whether to go to battle or not.