Freshwater Fishing photo

Sure, it’s a great fishing knot. But the fact that the double fisherman’s knot joins two lines with a streamlined profile makes it perfect for lots of other jobs, too. Used with old flylines, the knot has just enough bulk to make it perfect for replacing broken zipper pulls or constructing sunglass tethers.

With 6mm or 7mm rock climbing accessory cord, it makes awesome grab handles for duffels, canoes, and coolers. You can learn to tie it blind-folded, or more usefully, in the dark, which comes in handy when the wind is howling and you need a longer line to stabilize a tent. Get practicing.