If a girl is into you then you can use the flimsiest excuse possible to get her back to your place alone and it will work. One time I got a girl back up to my place (for the subsequent f-close) by asking her if she wanted a glass of water!!
As long as you have done your job right you can say anything short of 'come back to my place so we can fuck.'
To be honest, I kind of prefer to weasel my way back to the girl's place. As long as she doesn't have obstacle roommates etc. I think it is the ideal location... she is going to be very comfortable in her own place. I also think that if a girl brings you to her place that she is demonstrating a higher degree of comfort and trust than if you can simply get her back to your place. (i.e. you know where she lives now etc.). There is a classic Mystery/Style line that's something like "so if I let you take me home with you what are you going to feed me? I'm serious, I'm hungry!" .... and if she's into you she'll just start listing off what's in her fridge.