I made a graph for comparison purposes.
It is assumed that:
a) all necessary ingredients are collected by others and deposited near you (of course, "others" can be your own alts)
b) All your relevant stats/skills are high enough so that no softcaps take effect.
Note: bread includes both turning wheat to flour and flour to bread dough. Would be more if the flour was also produced by others at fast enough rates - however, that's probably more than one person can handle even with multiple clients.
My favourite is producing cloth, as that method of gaining LP actually produces something useful. With a decent quality loom, it beats dowsing rods when using regular q10 branches.

Comes without warranty.
Edit:
click here for the larger version - was too large for the forum.