Since I don't use leadouts, the throttle line will be several inches longer than the elevation lines. When I tie the lines, I shoot for a handle to fuselage length of 60' 1". I usually make lines for each airplane, and make them on the airplane. I make up the airplane ends at home, then make the other end at the field. I make the up line first, and this establishes the overall length. Then I make the down line, which establishes the neutral position of the handle and elevator. The throttle line is last, and requires a bit of fiddling and trial and error to get full bellcrank movement. Definitely a two person job. When making the end, I start a few wraps of copper wire to hold everything in place, but I can make minor adjustments to the length by pulling the line through the wraps one way or the other. Once it's right, I'll finish the wraps. Most of the time I can be accurate enough that I can use the same size line clips on all three lines.
One thing that I have found to be extremely helpful is to pre-stretch the wire before making up the lines. Due to the way stranded lines are made, there is a bit of elongation when they first have a load applied. This is enough to mess up your precise line lengths. I initially cut my wire to about 62', and with a helper, give each piece a good tug before making up the ends. The bit of extra length gives something to wrap around a rod or screwdriver handle for pulling.