You should already know how to tie the Uni-knot from the instructions for tying the Double Uni-knot, which is just the first half of the Double Uni-knot and used for tying the line or leader butt to the PVC coated fly line. The same knot is also used for the fly to tippet connection, but in that case it is often called the Duncan Loop. The Uni or Duncan Loops have the advantage of being able to be tied out in front of the fly so its hackle does not get messed up. Then the loop can be tightened down to the hook's eye or left open slightly for better action on jigging type wet fly presentations. When a fish is hooked and played the open loop will slide closed but it can be pulled back open again for the next presentation. Here is a link for how to tie the Duncan Loop: http://killroys.com/knots/duncan-loop-or-uni-knot/ and http://www.netknots.com/fishing_knots/uni-knot/
Here is a video showing how to tie braided line to a fly line but it also works just the same with mono, whether it be nylon or fluorocarbon line. Again the Perfect Loop is also shown but you can quit the video when you get to that point. http://www.youtube.com/watch?v=NWorbh8BBpY
As a final note it is a good idea to Zap-A-Gap weld all of your permanent tapered line knots together. There are a lot of super glue brands out there on the market but Zap-A-Gap is the only reliably waterproof super glue on the market. Loon UV Knot Sense (which will cure in natural sunlight just fine so you don't need to buy their Loon Mini UV Lamp if you do not want to buy it) can be used to form a smooth coating over all the tapered line knots you tie to help prevent the line and water debris from catching on the knots.
Last edited by Golden; 04-26-2013 at 12:17 PM.