The way I feel about it is co-sleeping helps a baby/child feel secure and safe sleeping in the early months years. I am co sleeping with my youngest (fourth) at the moment who is 16 months old. He can sleep alone through the night no problems, but I really like cuddling with him so I actually take him out of his cot and put him in bed with me - I know - bad mummy... probably because he's my last baby....
Anyway, I don't worry about him not being able to sleep alone. I already know he can. His cot is in my room. At some point, I will move it out into one of the sibling's rooms. None of my other kids have had a problem sleeping in their own beds. They don't even wake up and cry at night or anything. I attribute that partly to them having a secure co-sleeping experience.

As for how I co-sleep... I just cuddle my toddler while in bed lol