Re: Beginner nymphing?
IME...don't be afraid to go with the lightest reasonable diam. tippet = 5x for example. True, you might get hung on botton obstacles a little more, but the lighter tippet will give your imitation a more natural drift and will produce more and bigger fish. 5x is strong stuff...unless you're going over #12 patterns, 5x might lose you a few more flies, but will produce more shows...IME.
*One thing...imho, make the section above your tippet over 8" and your tippet over 12". Both sections will produce more stretch than will very short sections, thus you won't break as many fish off. I know it'll seem a little more nuisance with a long leader but it'll give the two thinnest sections some room to stretch. The rest of the leader doesn't have to be that long = its burliness won't be as apt to break..