Depends on the farming usually. When gold farming or doing some intense farming, I listen to music. When farming in general, I can multitask and do things like check Discord and Twitter, watch a YouTube video, listen to music, and much more.
I dont know if i can call it farming. But mostly, i read books, sonetimes plain farming / chatting, eating etc
Make sure to take frequent breaks as well, like every 20 minutes. Stare at a wall from a distance to lessen eye strain and stretch your body to get your blood circulating and relax your muscles.
Yeah normally I stretch or get up and walk a bit or change positions. Something like that. Till it's meal time or I'm just to tired to continue.