For the minutes I can not help you. However for the data make sure your devices are connected to as many WiFi networks as possible. Especially at home or at work (if available). This will help your keep your cellular data low. Also make sure there are no apps using data when your phone is on standby. Weather apps are the worst about eating up data because they're checking for weather updates constantly. Hope this helps.
AT&T Galaxy Note 3 Rooted/Dynamic Kat 4.0