thanks for the ping to this nice story. Now your question
I have had A LOT OF CATS (and only 2 dogs)over the years having been involved in rescue & being a place where many get dropped.
One of the keys is to NOT fuss over the new pet. The mentality is the new pets are your "current dog/cats pets." Give extra attention to the older pet & talk about his/her kitty.
Cats I find are like people. some are easy going and hardly lift an eyebrow & some are very jealous & will be mean spirited & territorial. all the techniques in the world can't overcome some.
A male will normally accept a female more readily but most of them after a few days of tension settle down & enjoy a playmate & companionship, if only to share a cuddle spot on the bed or sofa.
FOr some a few days of getting acquainted under a door. Put new kitty(ies) in room & let the new/old meet by smelling & doing the "paw under the door" play thing.. They will still hiss when then nose to nose & some fur might fly but it will not be the total shock.
Make sure all pets have thier nails cut back to minimize thier eyes getting cut & your skin being slashed. Do NOT cut into the red artery you can see. I use regular nail clippers
One thing I have been semi-successful with is introduing them & having two piles of catnip.. at least 4 feet away. Each gets high in their own pile, as they eye the other. They will probably trade piles a few time with old cat taking over the new cats.
Keep us posted & good luck!
Great suggestions Dolly Cali, I've got two altered male cats who came to me at separate times and, unfortunately, they don't like each other. This has been the case for over 4 years now. Wish there were a way to solve this problem. They'll sleep within 4 feet of each other and be fine but once awake it's no holds barred! I'd LOVE to get a female kitten that I could cuddle, but afraid since they don't like each other how they'd treat the new one. I'm tempted since it would be a female kitten, but just don't know. Any ideas?