nap time struggles

My baby girl is 6 months old. I just got her to stop nursing to nap. But she has to be walked around and when I put her down 3 out of 5 times she'll wake up and be wide awake. If I walk away that's when she'll cry. I've tried rocking her then putting her down before she's asleep- but she just wakes up and smiles. I've tried putting her down then patting her while "shushing" her. I'm nervous she's too old to need these crutches and we're in for bad sleeping habits :( Any advice?