I need to buy a new spool of serving and am unsure of what diameter to buy. I see there are a lot more serving material choices too.
My strings are 3 bundle, 15 or 18 strand fast flite. My nocks are usually 5/16 snap on classic nocks.
what would be appropriate for my setup?
I only use BCY products, so I'm no help here. One thing I can tell you is the size will vary depending on the material; i.e. .026 Angel Majesty is a little smaller than .025 62XS or .024 Halo. .025 Power Grip is a little larger--I think because it stays rounder.
Clay from TG here shows this tutorial. He uses fishing line.
https://www.youtube.com/watch?v=aPEv_R8dSQc&feature=player_detailpage