Cut the long cable into two equal lengths. On one end of both wires add the rod end as you hve done in your picture. Try to crimp each tube twice, once on each end in opposite directions. Make those crimps very tight. The heat shrink only adds looks and weight, nothing more. Attach the cables at the servo end after running them through the fuse. Install the clevisis and rod ends on the rudder horns without the wires. While maintaining the neutral position of the servo by having the radio turned on with the travels and sub trims centered, run the cables through the rod ends at the rudder horns. Be sure that the rudder is centered also. I like to use a couple of long sticks or arrow shafts, rubber banded together on both ends, with the rudder between them for this purpose. Try to get them pretty tight, but not tight enough to sound like a high pitched guitar string. Medium to high bass string will do. Crimp the tubes like you did on the servo ends and then adjust as needed. Don't forget to leave yourself a little adjusting room on the threaded ends when you assemble the wires.

There's prolly another hunderd ways to do it, but that's how I get it done.