Just as with a real baby, a sling is a must for carrying around your doll.
I had to (really, I just had to!) make James the sling after we went to the library and he wanted to take his doll, but all he had for carrying was the Moses basket bed. So he lugged that thing around with his doll and two blankets draping out of it.
I have to say, either way, there are few things more satisfying in life than watching your child play with a (and love) toy you made them. So sweet.