I mean the one basic rule of threesomes is just make sure both girls have chemistry, usually you have a girl you already see and like, and have her tell you the girls in the house she likes to work with
Regarding threesomes I've read amazing reviews on Vane Pornstar, Caro Fereira, and Tifanny. I think Tifanny is on hiatus, but Vane and Caro still doing the threesomes.