Question About Sniffing on a Specific Device on a Network

Hi,

so i gained access to a wireless network( its a WEP it was pretty easy )

and i would like to sniff on a specific device on that network(a mobile phone).

My question is what would be the best way to do that in kali?

I know there is Wireshark, tcpdump, ettercap and all that, but what would you choose to do that and how should i procede to capture the traffic on a specific device.

Also how should i procede to see if the device is on the network.

Thanks.

--PS :im more asking to the people who are experienced hackers.