Create a file in udev rules folder under config, called 99-mac-address.rules
Add these lines with whatever mac addresses you want. This will stop random macs etc.
SUBSYSTEM=="net", KERNEL=="wlan0", RUN+="/sbin/ip link set dev %k address D8:FC:93:6F:29:2C"
SUBSYSTEM=="net", KERNEL=="eth0", RUN+="/sbin/ip link set dev %k address D8:FC:93:6F:29:3C"