There are many variables to making the client decision easier and design a good RF environment but if you want to try something easy that might make a big difference, try this:
1. Configure the SSID only to use 5ghz band (band a). **WARNING** If you´re not positive all clients using this SSID supports 5ghz, don´t do this. The 2,4ghz only clients won´t be able to see the SSID anymore.
2. If you have 802.11ac access points, make sure you disable 80mhz channels.
Cheers,