The Skills Which Increase Reprocessing
There are only a few skills that are important to reprocessing. These are Reprocessing, Reprocessing Efficiency and the ore specific reprocessing skills. The list below shows what each skill does. If you have not trained any of there skills, or are in the middle of training them, I would recommend the following order:
First get Reprocessing to level IV followed by Reprocessing Efficiency to level III. Next train the ore specific skills which correspond to the ores you are mining and processing to level III. For example, get Veldspar Processing to level III if you actively mine and/or process Veldspar. When that is done get Reprocessing Efficiency to level IV followed with Reprocessing to level V. After that train the ore specific skills to level IV. Finally, you train Reprocessing Efficiency to Level V and complete it with the ore specific reprocessing skills.
Where to Reprocess for Highest Yield.
You can still reprocess at the NPC stations using the base 50% installation. It will however never give you a higher yield than 70% at maximum skills. This can be pushed a little with implants, but not by much. You should instead try to reprocess your ore, ice and stuff in citadels.
Citadels are player owned stations which can be found all over Eve now. They have the ability to fit reprocessing rigs that increase the base yield from 50%.
In high-sec, you can find Citadels which offer 54% basic yield. In low-sec, this can be up to 57.24% and in null sec or WH space, you can find citadels with 60.48% basic yield.
This can at first seem small, but the difference in 50% to 54% citadels when mining in high sec is huge over time and as your skills increase. For example, a character with max skills and the best cybernetic implant can get at 78.14% reprocessing efficiency at a 54% citadel compared to 72.35% at a 50% NPC station.
This means that for every 100 million in ore you mine, you lose 5.79 million for no reason. To top this, the NPC stations usually have a higher reprocessing tax, resulting in a further loss.
This difference is even more profound in null sec where you can have over 10% difference in basic reprocessing equipment efficiency. Giving you a whopping 87.5% reprocessing efficiency at the best citadel, with max skills and implant.
It‘s worth to note that the medium-sized citadels might only offer the added yield to specific ore or ice. The large citadels can offer yield increase to all ore or all ice and the extra large citadels can offer the yield increase to everything. So if you are setting up for mining you should check out what the citadel is offering. But the bottom line is, you should always reprocess at a citadel if you can.
The Cybernetic Implants.
There are three cybernetic implants that can increase your reprocessing yield. These are the Zainou ‘Beancounter’ Reprocessing RX-80X, where X is either 1, 2 or 4 depending on the quality of the cybernetic implant. The best of these implants are expensive, but if you process a lot of minerals they pay for themselves rather fast. For example, by using best high sec station and max skills, you would gain 3 million more ISK with the best implant for every 100 million ISK worth of minerals.