...I have also made 100% lard. Nice, very gentle soap but it very lacking in lather. A better combo is 80% lard, 20% coconut.
That's been my experience as well -- an all-lard soap is mild and long lasting, but it doesn't necessarily lather all that well. Add 15% to 20% coconut and the result is really pretty nice, especially after a generous cure time. In my experience, a mostly-lard soap is decent after the usual 4-6 week cure time, but will improve a lot as the months go by.
I normally use a little less lard for most of my batches, because I think a little less stearic and palmitic acid and a little more oleic acid helps the soap to build a nice lather quicker and more easily. My current recipe is similar to Susie's --
Avocado Oil 5.0%
Coconut Oil 15.0%
Sunflower high oleic 20.0%
Lard 60.0%
The avocado is in there for fun and label appeal. If I didn't want to use it, I'd add the avocado's 5% to the sunflower.
One could sub any high oleic oil for the sunflower -- olive, safflower, canola, etc. You'd want to use a high-oleic or mid-oleic version of these oils, not the conventional high-linoleic type.
Another tip to increase the solubility and lathering ability of an all-lard or high-lard soap is to use a "dual lye" mixture. I normally use 5% KOH and 95% NaOH, rather than all NaOH.