Introducing Cats

How do I go about introducing a new cat to a resident cat?

It is virtually impossible to predict how one cat will respond to another. Personalities may clash! But please follow these general guidelines:
1. Take it slow, it is harder to repair damage than to prevent it.
2. Spend extra time alone with each pet.
3. Allow frightened animals a chance to get away from stressful situations, do not block escape.
4. Consider owner and animal safety.

Phase 1
First few days, confine new cat to one room with a litter tray and water, spend time in there with it.
Resident cat will smell and sense intruder, reassure resident cat.
Feeding relieves anxiety, feed the cats either side of the door to the room where the new cat is confined, moving bowls closer together.
Move only as quickly as both cats seem comfortable with.
Confine resident cat to an area that it is comfortable with and allow new cat to explore house until both seem relaxed. This may take days or weeks.

Phase 2
Arrange for a time when both cats can roam freely together. Coincide with meal times. Expect some hissing and hesitation while they assess each other.
Feed your cats in each other's presence at a comfortable distance apart and then separate again. If either will not eat, try again later when they are relaxed.
Allow them to spend longer and longer together after meals and move food bowls closer.
Only consider the use of medication if absolutely necessary and under the direction of a vet or behaviourist.
Resident cat's emotional state should be given priority over the newcomer.