I tried watching several tutorial videos and I’ve seen a couple of threads on this, but I was wondering if you guys had any other tips on how exactly to hold the string and pop the yoyo up in Eli Hops. I understand the concept but it’s still a little vague to me how I’m supposed to hop the yoyo up in the first place. Should I use my NTH or TH to hop the yoyo? Should the catching string be slanted or straight? Any tips would help immensely. Thanks.
Eli hops was a very weird trick to learn for me so I understand your frustration 
I found that the initial “jump” of the eli hop mainly came from trial and error experimenting with the freehand putting more “power” into the jump and the throwhand. To get the perfect jump is a balance of both the freehand and throwhand pulling apart. I find that the greatest motion comes from the throwhand myself.
Worth noting, careful not to let the yoyo hop towards your throwhand. Either straight up or out toward the freehand, otherwise you’ll get a kind of wonky looking eli hop that might lead to problems in the future.
Good luck learning this trick! Its really rewarding once you start getting it. Hope I could offer some help!
Contrary to my username, I do actually know how to do this trick well (well enough anyways)
I find that most of your hand movement comes from the non throw hand, pretty much all of it actually. I keep my throw hand still while doing them. Use your non throw hand to pop the yoyo up and pull it back down. The yoyo shouldn’t just drop down back into trapeze, you pull it down by extending your nth back out; there should never be any slack in the string.
When I say pull the yoyo back down, I don’t mean to grab the string or anything. Let your nth finger slide along the string.
Also, I turn my torso a bit as if shifting towards front style. I turn counterclockwise (I throw right handed) just a bit.
Oh and don’t try to do big ones at first, start with small hops.
Hope this helps!
pull in and out your hands
step 1
(hand) <------------- > (throw hand)
step 2
(hand) --------><-------- (throw hand)
repeat