I can at least tell you what works for me. I use a 7 1/2 to 9 ft leader at least 2x, maybe 1x or 0x, depending on how big the bass are where you fish. In most of the water I fish, the bass can run to 6-7 lbs. If you are fishing large flies (I mean large, like 3" long or more), then the tippet needs to be pretty strong to turn over the fly without collapsing the leader. Hope this helps.