What I have planned so far (I've only just hit WW 73.3):
level Bonecraft to ~53:
90-91 - Kabura Arrows x33: Earth Crystal, Bamboo Stick, Karimata Arrowheads, Giant Bird Fletchings, Ram Horn
91-95 - Bldwd. Lumber: Desynth
Soulflayer Staff (Wind Crystal) or synth from Bloodwood Log. Staves are cheaper.
95-96 - Lqr. Tree Sap: Water Crystal, Lacquer Tree Log
96-98 - Cythara Anglica: Earth Crystal, Ebony Lumberx2, Coeurl Whisker, Ancient Lumberx2
98-99 - Lancewood Lbr.: Wind Crystal, Lancewood Log
....And a tie between break-synthing
Iron-splitter and/or crafting those into
Steel-splitters; and
Staurobow.