Attacking strategies

Attack all out. There is no point in sending half your guys to lose when all could win.

Also you should control your guys throughout the battle. Many battles can come down to who controls their guys better.

Another good thing to do if you cannot win is to go right past them and kill all their peasants. Unless they have a huge surplus of gold it will take them a while to get back on their feet and will not be able to make more guys. While they are trying to recover you need to attack over and over until they are finished.

When attacking a town, go for the peasants. Without peasants they have no gold. Without gold they have no army. After the peasants are gone take out their towers and any remnants of an army they have left. If they have 4-6 barracks its useless to try to destroy them all because they can just train out of another. Take out smiths, stables, and mage towers first.