I fish about 90% of the time with my wife.
My fly knot: Orvis knot (just like ^^) It's a superb knot, and I've now confirmed (after getting snagged in rocks) that my orvis tippet to fly knot is stronger than the uni/uni further up on the leader!
Think I'll switch to triple surgeons permanently....
My wife's knot: Improved clinch -- all she will use. She does fine and seems to tie it really well. I do NOT, so I don't use it. I've read that clinch knots are weaker if you are using light tippet to large hook eyes...so beware of that on bigger flies.
Like everyone else mentioned, use a sufficiently heavy tippet for clousers or other medium/large subsurface flies. I think that people coming in from a "trout" background far, far
underline subsurface flies when it's not necessary or beneficial. I fish #6 and 8 clouser minnows on a 8 pound mono tippet -- never
smaller, and a 10#-15 pound mono would probably be just as good or better in heavier cover. I recently fished Mossy Creek, VA (a technical spring trout stream with a LOT of stuff to hang yourself up) with 8# tippet against the common "wisdom" of using 5x-6x! It is so taboo to use such heavy tippet that I am afraid to tell anyone here locally. That said, I did fine and caught a few fish without problem. I did hang up and the heavier line was much better at getting "un-hung" out there too.
Personally, I think the "divide your fly by 3" equation is useless
for anything but trout dry flies. I've read "divide by 4" for subsurface flies, which is much more realistic for me, but even that underestimates IMO when you add lead weighted flies into the equation. If you use a 6X tippet on a 6 weight rod -- sure, you may get more bites. But good luck landing the fish or even playing
it properly on the rod without breaking your tippet. What's the point?
Just my opinion! I hope this helps.