Useful Knots
Double Uni knot
This is a great knot used to connect two pieces of line together. Think adding a piece of tippet to the end of your leader or connecting two pieces of tippet together to build your own leader.
Fishermans Knot (clinch knot)
This is the golden standard for connecting a fly, or hook to a fishing line. There are a few ways to tie it shown here.
Perfection loop
The standard for creating a loop in your leader or tippet that can connect to your fly line.