At the start of the game, after the King's convoy is attacked, immediately take the dead guard's katana and armor. This will make slaughtering rats and defeat trolls much easier.
To get easy guard's armor or weapons, you must be able to summon something stronger than a basic skeleton. Get close to a few guards and summon your creature, then attack your creature three times with a weak weapon (so it will not die). Your creature will start to attack you. The guard will start to attack the creature. If he does not, lure your creature into attacking the guard. Your creature will do minimal damage to the guard, then die. Repeat this process untill the guard is dead, then loot his body. Note: The other guards will not arrest you for looting the guard's body.
To create invincible armor, have your character be born under the Sign Of The Tower. Play normally until you are about level 20. Get five Grand Soul Gems and fill each one with a Grand Soul, then get a curaiss, boots, greaves, a helmet, and gloves. Enchant it all with your Grand Soul Gems with reflect damage. Nobody will be able to hurt you and will get hurt if they attack. Only mages and archers will be able to stop you, but they are easier to deal with.