Locke's Skill- Steal/Capture
Locke has perhaps the most useful skill in the game. Steal allows Locke to take items that enemies are carrying. This is a great way to get useful items, weapons, armor, and relics, without shelling out the GP. Really, why wait for Dragoon Boots to be sold in the World of Ruin, when you can steal them from Harvesters on your first trip to Zozo?
Speaking of your first trip to Zozo, in the central tower, (where you find Terra) you will find the Thief Glove relic. This item turns Locke's Steal into Capture. He will then not only be able to steal from enemies, but he will cause damage as well. There is a catch with this item though. If you are trying to steal something from a weaker enemy, you might kill them before they cough it up.