Hi!
If you are talking about as you indicated, Spark Plug wires etc. then I use electrical wire I buy by the foot at Home Depot. In the larger scales you can pull back the insulation a bit, Cut off the wire inside and it will leave you a opened end. Put that on a pre-installed brass rod pin and you are good to go.
When I worked exclusively in 1/8 and 1/16 I used the same type of wire, just different sizes and larger wire insulation, for short nubs for Spark Plug Boots. If you use the finer wire as is, with the opening on the end, the wire left inside will keep you from getting a crushed curve. Just don't try to make those curves too tight!
If it's absolutely impossible to get that, then use soft brass wire and a Micro-Mark Tubing/Wire bender! Using Solder is good too.My landlady does Stained Glass Crafts and I am always raiding her stash of solder for detailing my Planes.