With worker stealing, remember that if the AI is willing to make peace, that means you can steal another worker and immediately make peace. For the same warmonger penalty, it's better to get two or more workers - perhaps some caravans - so be sure to set yourself up for another steal and check to see if they're willing to make peace before moving. Consider what will be high priority tiles, which you can learn from observing as well as common sense (tiles with horse resources; mining luxury as they start the game with that tech).
Look for great situations, such as:
*hill tiles with mining resource in 2nd ring with a river between the hill and the city hindering melee attack
*high priority 3rd ring tiles
*for city on flat land, 2nd ring tile on hill or with a hill in the way, so that a ranged unit in the city cannot attack you. Less common, but same idea with a mountain between the city and 2nd ring target tile.
You can be more aggressive with CS, since you can make peace immediately; but, you can similarly try to set up repeat steal scenarios to maximize your one 'free' CS DOW.