In watching many of the threads about lines, and leaders, and seeing there is much about knots slipping, I thought I would put in my 2 cents. For years and years I have used the improved cinch knot, and the blood knot. I have had knots slip, and break. A few years ago I started using the uni-knot to tie a fly to a leader, and the surgeon's knot to buildup a leader. A built up leader does collect mung, but so does any knot. I have not had a knot slip since I have been using the uni-knot, whether I use fluro, or nylon. I like the thoughts of being able to have a free swinging fly at times, which also takes up a lot of shock when a fish hits. This year, for instance, I haven't taken the fly of my leader in about 4 weeks, been using the same fly, and have caught about 30 fish to around 30 inches long. I have been dragged around rocks, in the sand. The fluro leader I have been using still doesn't have any nicks that I can feel. The lightest tippet I have been using is 16 lbs. The uni-knot is fairly easy to tie. Just put the tippet through the eye of the fly,bring the tag end up alongside the standing part, make a loop, and take about 6 turns through the loop, wet the knot, and draw it tight, one very strong knot. If you don't tighten it up against the eye of the fly you have a free swinging fly that also acts as a shock absorber when a fish hits, I haven't found a knot that works as well yet.
Try it I think you will like it. I think of all the good fish I have lost do to knot failure in 58+ years,the big fish always gets away.