Fluor is definitely the best leader. If you use an attractor ahead of the lure, then you can go mono to the attractor and fluor to the lure. 4# or 6# may be fine for tying right to a lure but you should step up to 8# or even 10# fluor when using an attractor or flasher / dodger. If you use a dodger, go with the 10#. Lighter leaders can get all tangled and twisted, even with swivels, from the action of tha attractors. I got these tips from Alan at AJs bait and tackle.