It's up to you. It will be more a visual thing than anything else. Unless you can machine the end of the pocket and the end of the neck on a CNC machine or a complicated router jig (preferable CNC made), getting the curves to match exactly is nigh-on impossible.
I've used chalk on the end of the neck pocket to mark the touching spots on the end of the neck before, and using that method you can get quite close to a match, but still never perfect. It's very easy to just keep going and then you find your neck is 2mm shorter and the neck pocket 2mm longer and you've still got a 0.5mm gap!