I adopted 3 catz about... 3 days ago. They were very shy, and unhappy.
I had a maine coon. She is sweet... and so, (the adopted petz hated eachother, so I did this one at a time) I introduced them to her. Love at first sight.
They now groom eachother (heavily) and play with eachother, and dance. (I did this one at a time, because they still hate eachither
And by the way, dancing is when one pet hops, perhaps multiple times, to get the other petz attention. Then they copy eachother, do back flips, funny walking, rubbing heads together, and affection etc. IT'S SO SO CUTE!) Maine coons are good for that kind of thing I think. Nanny is lovely to everyone she meets and makes friends easily, like she did with the other guys.
Since then, they warmed up to everyone and me. ALOT.
Also, feed them kibble, treats, etc. Don't use the squirt bottle, and pet them if they look at another cat funny istead of psyically telling them off. Sometimes it's just jealousy, and telling them off gave me a bad bond with an adopted pet of mine. It has since gone. (thank god... he hated me!)