I think everyone gave the right response, i use Amnesia , its red in color so i can see it well, nail knotted on one end and a perfection loop on the other. The real reason i use Amnesia is because of its flex. flex the end of your flyline, your leader connection should be just as flexible. i read this somewhere in a book , so its not my own idea, and i have been using it for years. i fish over some very picky fish in a C+R water that will look at a fly drifting for 10 feet before decideing to take it or not. every little bit helps.