You can find several threads on lacing twine if you search, for example http://www.jalopyjournal.com/forum/showthread.php?t=164464 I have mid-late 50s stuff so I use the non-sticky black plastic tape that they used back then.
I used a braided nickel on mine where it shows, a real pain in the ass and don't plan to add a wire later as you have to 'thread" the wire thru. Looks awesome like braided steel, just dont get a short or real bad things will happen.
I'm planning on using the nice woven fabric looms from sacramento vintage ford. http://www.vintageford.com/sect_search.cfm?Line=Hot Rod&Category=Wire Loom- Vintage
I still like my wires exposed and run neatly with small tyraps. most of wire customers like it wrapped with tape?