My approach to integrating pop culture into magical work is one that is informed by my understanding of the principles of magic. When I think of the principles of magic I don't think of ceremonial magic or tools or other such things. I think of what makes magic work and then I think about how I can apply pop culture (or other interests) to those principles. I don't go with just any form of pop culture either.
With pop culture entities, the choice is dependent on what is really popular at the time. The truth is that most pop culture entities don't have the same staying power that your traditional entities have. They become popular for a while, hit a zenith, and then fade away. Some like Harry Potter have enough staying power that you can work with them for a while, but the majority are fads, liked one day and forgotten the next. My choice to work with a given pop culture entity is based on what that entity represents as well as what it can do. I make rare exceptions where I'll work with a pop culture entity regardless of how popular or not its, but that's based on a deeper recognition that speaks more to the influence of the entity in my life as opposed to the world at large. If I do work with a pop culture entity its because I recognize that entity has significance in a way that I find useful to further my own work.
With techniques, I get pickier. I won't draw on the description of a given technique in pop culture unless I think it'll actually connect with the principles of magic. For example, in the Death Gate Cycle by Margaret Weis and Tracy Hickman, they included appendices where they described in depth how magic was supposed to work and how it interacted with possibilities. What I read made sense and when I applied it to my own magical work, I found that it worked. On the other hand I wouldn't draw on the Harry Potter universe's approach to magic because its mostly based on a push button/spell approach to magic. There's some explanation of how specific types of magic are related to emotions, which could be useful, but for the most part magic is never really explained in depth. You wave a wand, you say a word, and it just happens.
I also don't always draw on explanations of magic in pop culture for my inspiration in magical work. The book Understanding Comics by Scott McCloud has nothing to do with magic, in an overt sense, but his explanation of how comics work, particularly how they are read and the space/time dynamics involved have inspired a couple of techniques on my part that have proven useful.
I don't use every single bit of pop culture that comes my way. There's a lot of it that I don't see as useful or relevant to magical work, but I figure the people who develop pop culture probably do some research and/or just happen to put a lot of effort into explaining their particular universe and how everything works. And I respect that and if I think it is actually relevant to how I can meaningfully practice my own magical work, I'll use it. What makes magic work isn't the tradition or ceremonies...its your understanding of how it works and your ability to implement that understanding in your life.