Manipulate Stats
When your character levels up, you have to go through a process where depending on their class and level they will get certain statistical bonuses that are randomized. By saving after your character attains enough experience points to level up (but just before you actually level up the character) you can manipulate your statistical bonuses, resetting the game until you get the statistics. For example, in terms of hit points, which is based on a character's constitution, you can raise your character's hit points by waiting for huge constitution bonuses, resetting your game until that bonus is attained. This is a really useful trick to make hugely powerful parties. Just be patient.
Easy Gold
Buy and equip a Buckler and then head to the Eastings Merchant (who has an incredible array of powerful gear). With the Buckler still equipped, opt to sell it to the merchant. You'll get 7 gold for it, but it'll still be equipped on your character. You can then do this over and over again for infinite gold pieces, but it'll take a while to build a substantial amount up only seven pieces at a time. Just be patient.