One method of deep nymphing that is very effective and is catching on is the bounce rig. The bounce rig is a simple way to get weight and two flies on separate pieces of line. Be aware of your local fishing regulations, while most places allow you to fish with two flies, some do not.
The bounce rig is most easily set up by tying two lengths of tippet to the end of the leader with blood or surgeons knots and leaving two of the tag end of the knots from 6 to 12 inches long. Tag ends are the ends you'd normally trim down right to the knot.
I've found that Blood knots are better because the tags are at 90 degree angles to the main leader, so if your line is pointing down to the bottom of the river, the tags are parallel to the river bottom.
The nymphs are then tied to the two tag ends and weight is added at the free end of the tippet where the fly is usually tied. A square knot below the weights is necessary to keep them from sliding off the end of the leader. This rig can be fished under an indicator, by feel, or Czech style by actually moving the flies slightly faster than the current.
The advantages of this rig are that you can bounce the weights along the bottom and the flies that are tied to the tag ends stay just up above the bottom where fish are feeding. If you snag the bottom it is often with the weights and not the flies. Play around with the lengths of tippet and tags and the amount of weight to find what works best for you.