You will all know about the advantages of popping up your bait but this is my chosen method.
The curtain ring makes the rig quite free running and as well as being a good stop the cork ball helps keep the ring out of any bottom debris.
I prefer to fish my popped up deads directly off the lead as I have found this to be more tangle free and safer. I also prefer to use my home made pop up sticks (once again have a look at the Tackle Workshop) These are attached to the treble with fuse/trace wire, you can if you wish just attach a poly ball and have this outside the bait (i.e. on its nose).
For a normal ledgered dead I use the same set up as above but with a 24″ trace and no pop up stick.