I have done quite a bit of leylandii. George is right, turn it wet and thin, or at least even wall thickness. Try and get the best finish you can while still wet. Depending on the grain orientation, it will distort quite a bit whilst drying out, therefore turning once dry may not be an option any longer. When dry, it tends to rip a lot easier than wet, even with freshly sharpened tools, and then you have a sanding mission.
It produces wonderful grain patterns, which can be enhanced easily with stains or dyes. Have a look through my gallery pictures, there should be some examples.