S&S brings up a good point. Most knots fail because they aren't tightened down correctly. Most guys use saliva to lubricate the knot before closing it down. Bill Nash actually recommends against saliva for knots formed in FC, but that's another thread.. When I'm tying knots at home I use a product called Knot Perfect which works way better than saliva and creates incredibly small finished knots that just don't fail. I also have a container of this when I fish out of a boat and use it then, too. I guess I usually resort to saliva when wading, though I rarely wade anymore these days due to physical issues. Knot Perfect is a George Gehrke (RIP, George) product. He's also known for Gehrke's Gink, Whale Spit, and the Marryat (later George Gehrke) fly reel. All three non-reel products are the best. Knot Perfect is incredibly good at what it does. Gink is a superb floating fly treatment for flies (that and original Mucinex are all I ever use on Bombers for steelhead and Atlantic salmon.) And Whale spit is the best thin lubricant I've ever used on fly reels. When your reel has an oilcap covering a tiny opening to drip oil into, it's the best. Other good oils like Hot Sauce are better when the reel is opened up for maintenance. Gehrke products are now distributed by Angler's Image which I think has been absorbed into one of the large wholesale companies whose name escapes me right now (Wapsi, maybe?)
On another note, the knot S&S refers to as the Ligature knot is also well known as the Simple Blood Knot in many of Lefty's books on knots. Same knot, different name. Not as simple to tie as one would expect with that name, but works well after some practice. I use it mostly as the knot to tie tippet onto my leader. That's usually the weak point in the leader when other knots are used (blood knot, surgeon's knot, etc) especially with the superb knots for tying on the fly. I'd rather have the breakoff, if it's going to happen, happen at the fly as then the fish isn't running around with a length of tippet as well as the fly in his mouth.