The recipes I know of are:

Wind Crystal + Goblin Mask = Sheep Leather
Wind Crystal + Yagudo Beads = 3 X Grass Thread
Lightning Crystal + Yagudo Beads = Bronze Ingot

Lightning/Wind Crystals on other pieces seem to be higher skill and the game won't let me attempt it.

Lightning Crystals are pretty interesting though. If you use it on let's say, an Onion Dagger, you will get a Bronze Ingot back. I need to try it on some other non smithing craft items, like trying to get some materials back out of a Cloth Cape, which wouldn't make sense logically, but could still work.

The splitting can actually be helpful in making money, as sheep leather sell for about 1k and a Wind Crystal + Goblin Mask (on a good day) can run for around 350gil total.

Well actually about Craft skills, anyone know a extremely good/complete site? Allakhazam's site is actually getting alot cleaner as people start to clear up incorrect information, plus the fact that there's a link to the item's page so you can see what the stats of the item you're making are. All the other sites seem to be using translations from Japanese sites which sometimes works, but on the other hand, the translation is off or SE might have changed the name a little for the NA release.

And who's actually pursuing crafting to a realistic degree. I'm trying to working up all my skills(Can make some good money this way if you know how), I've got 4 in carpentry, 3 in smithing, 5 in clothcraft, 1 in goldsmith,and a 1 in bonecraft on my Thf alt (I plan on becoming a RNG/THF and I'm seeing how realistic it is to make my own ammo) and I'm trying to get cooking up(currently 4) on my main so I can eventually make meatkabobs ( been bugged a few times about this from a few friends).