The single most important thing you can do to attract top talent is to move to a new city. Sure, if you’re a top world scientist people will follow you anywhere. This is not the case of most of us though. In the vast majority of cases, researchers looking for a new home will choose based on your location (this is specially true when researchers move with families!).
Myself, when looking for a post-doc stay, I first constrained the search to North America (I wanted to have an overseas experience) and from the great groups there I chose the one in the best city I could find (Toronto). I really never had to think too much if the quality of, for instance, Jeff Gray or Robert France’s groups were better than the people in Toronto, there was no way my wife accepted to move to Alabama or Colorado but she would settle for Toronto (her goal was New York but I couldn’t find any modeling group there).
Therefore, I’m sorry if your city is not exciting and/or you’re in a country where English is not the official language, most times you’ll be on the losing end of the battle to attract top talent for your team. My current location (Nantes) is not so bad but as far as I know I’ve already lost two good candidates due to “wifes pressures”. When this happens I just solace myself by eating Crepes (any location has always a positive side!).