I have typically used the clinch knot or non-slip loop, but I have started using the double Davy knot for smaller flies. The other day I snagged one on a branch in the water and broke it off. I could still see it so I took off my shoes and waded in (brrrr) to retrieve it. The knot was intact with about 6" of 5X tippet still attached, for what it's worth.