Lots of good info here. Seems the general concensus is long....or short.....or somewhere in between. Haha

Let the fish tell ya. When I do this, if I don't get bit, I'm changing baits or locations. Not wasting time on fine tuning a leader length.

my 2 cents, I use a 19 inch leader unless I'm in grass or timber then I use 36 inches in timber and I vary the length in grass depending on the depth of the vegetation I'm fishing, but you really should find a starting point that fits your style of fishing then tweek it from there after you start fishing. this will give you your best chances to learn how to quickly dial in what the fish want how they want it. But Hollingshead is very good with a c-rig so he probably has very good info on how to use it.