Q: Several of my fly-fishing friends have convinced me that if I use a loop knot, I will get more action from my flies. The trouble is, everyone suggests a different knot. Is there a loop knot that's easy to tie that you particularly recommend?"
A: I think a good knot should meet certain requirements. It should be nearly as strong as the material it is tied with. You should be able to tie it in different diameters, from very thin to heavy, with plastic-coated wire, monofilament and fluorocarbon. The knot should be easy to form to a desirable-size loop. And I think it's important that, when the loop is finished, the tag end point back toward the fly so it doesn't catch debris on the retrieve.
Having messed with a number of loop knots for all kinds of freshwater and saltwater fishing, I have settled on the non-slip loop, and that's been verified by my $2,300 line tester, which has no opinion.
A number of books show how to tie it. Even better, if you open Google and conduct a search for non-slip loop knot, you will find numerous instructional videos that will get you going.