I'm also a noob to breeding and trying to do something similar with fennekin, though I don't have power items yet.
The easiest way is like people are saying use a ditto (or female gabite with the IVs) and a power item against your male gabites to make a new gible with the IVs you want to then breed against the female. I started with no 31 in HP and had to hatch a few batches before I got one but if you have the power items yours should go a lot faster.
Basically you'll probably have to go through multiple generations before you can consistently churn out high-count 31 IVs. You'll also probably have to use multiple dittos/gibles. This is why friend safaris are so popular, especially ditto ones, because every pokemon in the safari is guaranteed two 31s and it's just a matter of catching the one you need.
>>15416766I don't know for a fact but I think you can only use one power item at a time if you want it 100% guaranteed. Power item and destiny knot also do not work together.
