(If you're trying to capture network traffic between processes running on the machine running Wireshark or TShark, i.e. If you are only trying to capture network traffic between the machine running Wireshark or TShark and other machines on the network, you should be able to do this by capturing on the network interface through which the packets will be transmitted and received no special setup should be necessary.
This page will explain points to think about when capturing packets from Ethernet networks.
