Get a bow or some decent spells and have at least 30 in Acrobatics. When the gate drops, run to your right toward where the right gate meets the fence. Jump onto the stone piece that juts out. Then, jump again to get on top of the little piece sticking out above it. Once on top, turn and fire on your helpless victims. When fighting mages or archers, stay on the ground and strafe behind the four central pillars for easy kills.
Go to the Imperial Arena and place a bet with the gatekeeper. The recommended amount to place is 100, as you are guaranteed to win. Then, go through the door up to the balcony where you watch the fights. While the announcer is giving the intro speech, Quick Save the game and let the fight go through. If your fighter doesn't win, select Quick Load. The fight will be different each time. Repeat this until you win the fight. This will always allow you to walk away with your pockets full.