I use a three turn Surgeons Knot for tippet to leader connection and a Turle Knot for tippet to fly. The Turle Knot is a lot like the Orvis Knot, the one used for the tippet to fly connection and in many ways a lot like the Davy Knot as tied by Davy Wotton. The Turle Knot has been around a long time and is great for fluorocarbon as well as for mono. There are different ways to describe the tying of the knot and some are very confusing.
If anyone wants a diagram on how I tie the Turle Knot and written instructions just send me a PM and I will email you the information.

Larry ---sagefisher---