Farming and material drop rate help

So I've been trying to get the hang of farming for Ascension materials for a while now. I have followed all the guides on here and elsewhere, so I understand that some quest areas drop more materials than other areas depending on the APD number (less being better).
I'm only as far as London right now, but I need more Ghost Lanterns and Evil Bones to strengthen my servants. Now for Ghost Lanterns, my best bet was at the Ghost Ship quest; so far, I only managed to get one Lantern after 20 tries in one week of farming. as for the other battles, 1 of every 2 battles resulted in either 1 chest of QP or no chests at all. It became clear to me that as APD of 67 was rather unreliable, and rather than waste anymore AP, I'd best wait for Nerofest or when I reach Camelot to increase my Lantern count.
So then I decided to work on my Evil Bone stock (I need like 27 more for Tamamo) and now I'm battling at the Giant Bridge in Fuyuki for the best results; but my luck is proving very unfortunate. After spending about 200AP at that quest (50 battles), I only managed to get 7 Evil Bones. So it is no different than my experiences with farming for Lanterns, except it feels worse on account of the many times battles gave me no chests at all. Calculating the probability of my poor results, I'm certain that I only could pop out a chest from a skeleton less than 20% of the time. One top of that, with only 7 bones from 350 skeletons, the chances of getting a bone from a chest was a mere 5% chance; so overall, only 0.2% of skeletons gave me any bones. This is not going well at all.
I've only been playing FGO for less than 2 months now, but I really gotta know if this is how farming is supposed to normally go for everybody else. Is there anything I'm forgetting to do when I take my servants farming, like do I need any specific CEs or Passive skills to increase my material drop rate chances? Are there specific times in the day when drop rates work better? Or is my luck just E-Rank?