In the Six Yogas of Naropa, the editor mentions that to do the six yogas it was considered essential to get initiation from a living lineage master, and that this belief is held to this day by the people who practice the six yogas. Reading that got me to thinking about initiation in general and also the fact that although I practice specific Tibetan techniques I have never been initiated into a lineage. I don't even know anyone in person who practices these techniques and I'll admit that I have practiced the techniques based on how I have interpreted the reading I've done, which means my own practice may not be accurate the actual practices (though it still seems to be effective and to generate the results that are supposed to occur).
Still I'm faced with a quandary. I can read this book and take the textual materials and translate them into practices, while accepting that I have not been initiated into a specific lineage, or I can find a way to travel to Tibet or somewhere else and get initiated. Knowing myself as I do, I'll more than likely read the text and do the practices, and not be concerned that I have or haven't been initiated into a lineage. What matters to me is the actual practice, and yet in a real sense I am missing out on that actual practice.
I'd argue that what I'd end up practicing might be similar to the six yogas, but it won't actually be the six yogas, because there will be something missing from the practice. What will be missing is the spiritual context that the initiation provides. I may be able to accurately do each practice and get results that are congruent that one would normally get, and yet nonetheless there will be something missing.
The main point of initiation, in a spiritual working, is that it provides you access to spiritual context, entities, etc. That access confers on you a specific kind of knowledge, a self-secret language, that provides connection with others in a similar way. And it also provides a layer of social access that is denied to just anyone. By being initiated you become part of a social order and culture that is part of the spiritual context.
On the other hand, beyond when I was given Reiki Attunements, I've never been initiated into any magical practice or order. I've taught myself. I've read books, practiced what was written and then modified it to fit my approach to the world. And while I'll admit that I may not have the spiritual context for practices that others might have, I've also created my own context and found that it has worked very well for me.
I see the value of initiation as a spiritual practice, but I'm not sure its essential for being able to do a specific practice. What I think is really essential is the willingness of the practitioner to engage the practices and incorporate them into his/her life. I've begun doing that with the six yogas and already noticed a change in my Tumo workings. What else can be asked beyond the sincere desire to engage the practice as best one can and meaningfully implement in one's life? For me that is the true initiation and it is experienced everyday.