HI J.,
I just wanted to tell you, now that my kids are 5 and 7 and are actually sleeping, It sooooo has less to do with me and what i did,It was all about their personalities.
I tried cio and it was NOT good. I listend in to another friend do cio several years later and there was such a difference, My child was HYSTERICAL, her's whimpered for 5 mins. NOT THE SAME. There is a difference in how babies cry for different things, and you have to trust yourself to know if they are giving you a sleepy whimper or if the world is ending.
for a 3 mo i would probably do dinner, bath, one little board book with the lights dim, 1 little lullaby and put the baby in the crib drowsy (HA my kids never had a drowsy it was awake or asleep and then i put them down adn they were awake again.) you don't want to stretch your routine out too long, if they yawn cut it short.
I would move a sleepign bag in on the floor by the crib and sleep there for the first few hours and then gradually wean from that, but i always felt better being close by. during that transition.
No stuffed animals and blankets!!