It has nothing to do with whatever Beings you call upon, whatever rituals you use, whatever tools you create - it's simply you. The main thing that all magick has in common (apart from energy), and is often overlooked - is you. You as a practitioner.
Look at, for example, starting a fire. You get a nice little area, place the tinder and stack the wood on top. You have the fuel for the fire - but there is no fire. So, you take a flint, strike it to let the sparks fall unto the tinder and voila! Now you have a fire. Magick is like a fire - the wood is your ritual tools and implements, the tinder is energy/ether, the sparks from the flint is will and desire, and - most important of all - the flint is you. Without the flint, you can have whatever kind of wood you want, whatever tinder you want, whatever area you want - there will be no fire. Same with magick - you can work with whatever you want, use whatever tools you want, use whatever methods you want...it doesn't matter. What matters is you.
We have written about this in many places - however, it's an important factor that should not be disregarded. Many books written on magick is flawed due to this - the author claims that if you do not use their methods, their rituals, their Beings - you will never succeed.
This is why not all meditations, spells, rituals etc will work universally perfect for all practitioners alike - as each individual is unique and have different mental and spiritual requirements and viewpoints. This brings us down to - if you cannot associate with something, it won't work - whether it's a Daemon, Construct, Ideal, spell or whatever. Here follows a good example:
Joe Black is a LHP practitioner through and through in both beliefs and ideals. He makes use the the Averse Banishing Ritual of the Pentagram and it works wonders for him. One day, he tries the RHP version - and it simply does not work at all. At the same time, Samantha White is an RHP practitioner. She makes use of this same RHP version daily with 100% success - and when she tries the Infernal Middle Pillar ritual...failure. Why? Because of their personal viewpoints, associations and beliefs. Does it mean that one method is bullshit while the other is not? No - it simply means that you need kindred association with all your workings. You have probably heard or read concerning placebos or placebo effects as well - it works for the same reason - your belief in it. The Buddhists clearly state that if you do not have the belief, you will not succeed - and this is for good reason.
Here are a couple of points to keep in mind:
2) Spiritual Growth
With these three points, you will always be successful within reason.