The Blood knot is best, but for the tippet knot you can also use a double (or triple) surgeon. I like it, it is quick and easy and strong.
Like many, I have used the improved clinch for many years. But I moving away from it as it is rated around 60%, which is really bad. I think I stick with it because I've used it for as long as I can remember.
New knots that I like and am practicing (so that when I finally get to fish again they will come naturally) are the Orivs and Trilene knots, both are rated about 90% strength and are no more difficult to tie than the improved clinch. As a matter of fact, the Trilene is so similar that it is quite easy to make the change, basically it just passes through the eye twice with another small modification. The Palomar also passes through the hook eye twice, which can be a pain - but on larger flies it's really not hard, and once you have that the rest of the knot it very simple.
There is a nice table of knots with simple illustrations that I like, but it's on a different forum site. Not sure of the etiquette for linking to other fishing forums so I'll (k)not do it.
Obviously, all you have to do it search the knot names and you'll find plenty of resources and how to tie tutorials.
---------- Post added at 10:20 AM ---------- Previous post was at 10:18 AM ----------
Originally Posted by Diver Dan
For the loop to loop attaching my leader to my line I use a perfection loop. link here
For building the leader I attach the sections with blood knots. link here
I almost always tie the fly on with a Trilene knot. link here
I trust all of these knots.
Great links, Dan! I was typing while you posted that. I do like the Trilene a lot also.