This whitepaper details how to perform wifi man in the middle attacks and then sniff the traffic for analysis afterwards using Wireshark.
You can download it from the following link: https://packetstormsecurity.com/files/download/126315/wificapture.pdf
Source: https://packetstormsecurity.com/files/126315/Wifi-Packet-Capturing-Session-Hijacking-Using-Wireshark.html