Hint: Easy experience:
Continue after defeating the first evil king (the rat). After defeating second evil king (the fish-like creature), return to the place where the first evil king was located, in the sewer. Once you get there, you will see bars that resemble those in a jail cell. Approach them and wait. A ghost will come after you. Let it get you for very good experience. The save and healer will also be nearby.

Hint: Easy Sukel:
In Tenel, go to the blacksmith's shop and talk to him. He will give you a Fruit Knife. Go to Madril and enter the shop. Talk to the kid at the counter and give him the knife. He will give you 300 Sukel.

When you get a new sword, sell your other weaker swords.

When you get though the Aquatic Ruins, you can keep returning to fight the earns to get more Sukel and experience.