I just recently started long line euro nymphing and had no idea where to start so I just made this up. I use Berkley XL mono for the upper section of my leader. XL is a very limp mono and at the end of the day you can reel it onto your reel and the next time you use it its not all coiled. I start with 3ft of 17lb then 3ft of 14lb. I attach my sighter to the 14lb then my flouro tippet depends on the depth of water usually 1.5x water depth to my anchor.

For my sighter I like the fancy ones that Alain showed us how to make. I usually make mine about 8 inches long. For measuring the 3ft lenghts I don't actually measure I just use a full arms lenght to my nose and then a few inches more since I'm 5'10'' and you cut some when you make your knots. I'm intersted in hearing what everyone else uses.

I think this is a somewhat short long line leader but as someone very new to this it casts very nicely.