I used this website to plan my GS items, and its worked fine for the ones I've done previously.

I had the exact ingredients it listed to make a pair of Acid blast Ooze shortswords, and made and combined the gems as instructed, but when applying the final tier 3 gems, I only had the following two options available to pick after combining an Earth and Water - Icy Blast + Sundering Ooze, or just Icy Blast.

So I ended up wasting 10 LDSs and the frost damage hardly works on anything and doesnt combine well with my Ninja Spy / Assassin using Porous Soul and Wind Stance.

But I get an army of oozes at least.