Most things are mentioned in Bamspeedy's article on AI attitude but there were a few things that I discovered on my own:
1. Using privateers on an AI is around a +4 on attitude for a few turns
2. Using AI workers to build colonies gives every AI a +1 towards you each time you do it
3. Very effective - When you ask an AI to leave your territory sometimes they back out but if you pull up the diplomacy screen again, talk to them again, you can STILL tell them to back out after they did as long as it's the same turn you asked. If you keep doing this, they will eventually get furious and declare war. It takes longer if you have a stronger military though. If they have an average military, 3 or 4 times is almost always enough. If they have a stronger military, once is plenty twice at the very most.
4. Renegotiating peace treaty where you ask them for things counts as a demand.
1. Using privateers on an AI is around a +4 on attitude for a few turns
2. Using AI workers to build colonies gives every AI a +1 towards you each time you do it
3. Very effective - When you ask an AI to leave your territory sometimes they back out but if you pull up the diplomacy screen again, talk to them again, you can STILL tell them to back out after they did as long as it's the same turn you asked. If you keep doing this, they will eventually get furious and declare war. It takes longer if you have a stronger military though. If they have an average military, 3 or 4 times is almost always enough. If they have a stronger military, once is plenty twice at the very most.
4. Renegotiating peace treaty where you ask them for things counts as a demand.