General Land Strategies

Peasants! You need peasants to win. The more the better. I always have over 20 peasants. Sometimes over 30. The more peasants you have the faster you can harvest resources and the faster you can make guys to attack. Lets say you have 10 peasants on gold and your opponent has only 5. In one trip you get 1000 gold, your enemy only 500. You have enough to train a knight while he can only make an archer.

Controlling your guys

When attacking an enemy, you should be watching your guys. When you approach your enemies base put your guys on patrol into it. A lot of people say to attack one guy at a time so he dies faster but I don't. If you have 9 guys selected and right click on one guy, only 3 can stand in front of him. The rest need to walk all the way around all their guys just to get to him. In this time his other troops will be beating on your back. If you use patrol, your guys will attack as soon as they come into contact. Then you can select individuals to attack.

Attacking buildings

When you are attacking a building don't use attack. Have your guys stand ground next to it. If you use stop sometimes your guys can be distracted if someone walks by. If you click attack 1 guy (even a peasant) can come up and kill your troops.
When attacking unit prducing buildings (barracks, town halls, etc.) place your guys so that when an enemy comes out you will have a 3 on 1. Or you can move in another guy and have a 4 on 1. Make sure your guys are on stand ground. If you use stop and a guy comes out and runs away 2 or 3 of your guys will follow.

Upgrade your guys!

Always upgrade your guys. If you are attacking early in the game it is vital. If your early invasions are lev.2 vs. lev 1 guys you can usually kill a few more of them and will last longer in the peasant line. A lev 5 footman can kill a lev 1 knight. Unupgraded knights are weak and useless.

Killing Peasants

The first thing you should go for when invading is the peasant line. Just park your guys in the middle of the line between the hall and mine. After a short time the ground should be littered with peasant bodies. This is a good way to seriously cripple your enemy. Now you can still make guys and they cannot.

Money

Never keep money in the bank. It's not doing any good there. You can't spend it when your dead and don't start with it in a new game. If you have lots of extra money, build more structures, such as barracks, mage towers, or even gryphons. It's silly to lose with money in the bank.