airmon-ng

airmon-ng "...can be used to enable monitor mode on wireless interfaces. It may also be used to kill network managers, or go back from monitor mode to managed mode. Entering the airmon-ng command without parameters will show the interfaces status."

Check for processes that might jack stuff up

airmon-ng check kill

Start monitoring mode

sudo airmon-ng start wlan0

Now you can use tools like airodump-ng to find APs and grab handshakes and such!