I’ve been trying to come up with something helpful - it appears to me that you, and perhaps a few others who’ve been getting frustrated recently, are applying theories based on science, in which a like action MUST lead to a like verifiable result (in other words, cause and effect MUST be replicable, or else they’re invalid) whilst neglecting to apply scientific methods of cumulative growth, research, study, and learning to yourself.
You expect (I don’t mean this in a disrespectful way) that if you, for example, cast a spell using the same methods used by someone else, that it must either work 100% effectively for you as well, or fail, in which case that proves that the spell is never going to be effective for you (and may in fact be bunkum, with other people’s supposed successes being down to coincidence).
So you’re applying the canons of physical science to magick, but in an incomplete manner.
Because what you’re NOT doing, is applying similar rigour to yourself - there, you’re indulging in literal “magical thinking” by expecting your results as a relative neophyte to match those of advanced magicians who’ve brought years of practice, pacts with spirits, plus internal changes like self-belief and faith in the process to every bit of work they touch.
You don’t NEED years of experience etc to get results, but you do need the internal alchemy they yield, which afaik is part of what the stuff E.A. teaches is for - conferring that alchemy gained through experience and practice in a condensed version, with the mistakes and non-essentials trimmed out, and with the core stripped down for anyone to take on board.
Right now, it seems to me that you’re not seeing the operator/magician as a crucial tool in the operation of magic, but are treating the work like a science student in a lab - two physical chemicals will react in the same way for a 1st year student or a Nobel Laureate, after all.
So this is just a matter of remembering that the definition of magick is “the Science and Art of causing Change to occur in conformity with Will” - and that therefore, the magician is a crucial part of the process, and in this case like actions won’t create like results when the magician is at a different place with regards to things like focus, belief, self-belief, and all other factors that can have an effect on the ability of their Will to manifest change.
In other words, the scientific model CAN be applied to magick, but it must apply equally to the magician himself because his Will is poart of the equation, and in some respects that’s where it more closely resembles art, in which the vision, preferences, innate skills etc of the individual will affect their output and influence the route they take.
In all cases (science, magick, creative art) practice makes for better results, and in all cases to throw things over as failures when you’re not even aware of the principles which have made them successful for other people would be a waste and a crime against yourself, robbing yourself of the things you hoped to achieve when you started down this path.
So, don’t give up, and don’t fall for the Harry Potter myth of some people just being BORN to magick, but neither should you expect to get the same results as another more experienced person, until you too have honed the tools of your mind and spirit in a manner comparable to their work - a process which is more about making the right internal shifts than slogging away for years, so don’t despair! 
