After sharing some personal tips on our discord server, the conjurers and I noticed that there isn't really much in the way of advice out there for witches who have to deal with the obstacle of aphantasia who wish to astral travel.
All my life I have struggled to visualize. I love the concept of reading but can't generate images in my head based on the text I'm reading. When someone describes what something looks like to me, I'll often blink at them with a confused and wide-eyed expression that is openly lost. Guided meditations that request you to visualize a door or a specific scene results in empty blackness. As someone with aphantasia, this is a very common occurrence for me, and as I have gotten more involved in the community I've noticed there are far more people out there that share in these experiences.
It is my belief that aphantasia doesn't have to effect your ability to astral travel. It can certainly be an obstacle that might need to be overcome, but the ability to generate imagery in your head is not a full stop.
I can't guarantee that the advice below will work for everyone who has aphantasia, but this is what I found worked for me. It took time, dedication, and effort in order to achieve the ability to astral travel in a more substantial way. It was progress I saw over several years and not over a matter of days or weeks. This is not going to be the quick and easy fix that you might be looking for, but if you're willing to put in the time and effort, these tips, tricks, and philosophies may help you achieve success with astral travel.
When I started feeling pulled towards witch craft and astral travel, I was fairly young. I had to learn to stimulate my third eye through meditation. I began with slipping into meditative trances and not worrying about where I was going or what I was doing. I will say, for the record, out of body experiences--at least in my personal opinion--are quite different than astral travel and can be dangerous. The goal with astral travel isn't to be fully away from your body, but to remain tethered during your trips, almost like energetic roots that grip you to the core of the earth so your soul or spirit won't get lost during its travels. In this way, you always stay anchored and have an easy out should you need to cut your trip short for any reason.
I practiced entering trances long and hard. For me it was much easier to get to this state of mind with the assistance of music. It didn't matter what music I used, but for others you might find music with lyrics or unpredictable transitions and shifts in tempo to be too distracting, so I advise picking music that works for you. Through these trances, I eventually learned how to pick up on energy beyond the basic five senses. I admit that back in those days I was quite young and unguided, and was using a lot of trial and error to figure out what worked, as I lived in a small town where resources and books of that nature just weren't available. On top of that, I didn't have a private computer until seventeen that wasn't monitored by my parents. There is a level of intuitiveness that comes with these practices, and while my situation limited what resources I had at my disposal, it's wise and recommended that you do your research first before you start attempting to astral travel.
From what I know now from research and developing craft relevant vocabulary, I was essentially stimulating the psychic function of my pituitary gland by going into these trances. Sitting in a low light or candle lit room with the lights off helped me to get into this headspace more easily. I allowed my mind to empty and listened for the hum of energy, letting the sensations come to me as they would on their own time. Eventually, I started to feel like my whole body was humming and vibrating almost at a different frequency. It was a very internal experience, and I think that a lot of people feel that astral travel is external when it isn't, which can lead a lot of people feeling they should be experiencing something more "concrete" than what they are. Once I mastered this mindfulness of energy and sense of awareness while remaining empty minded, I moved on to trying to meditate while in public spaces that were safe to do so in.
For example, on a bus ride back home from a school trip, I closed my eyes, and put my music on (it was Korn and Winds of Plague in particular I remember), and the music just kind of drifted away and became background music, yet I was keenly aware of all the energies around me, and with time and practice, that "feeling" became sight. That day in particular, I remember, is very clear in my mind. In that meditative state with my eyes shut, the shapes of the objects around me filtered in like a foggy film, and I could see every person who had been on the bus, all talking and interacting and moving around, and it was kind of like looking through a piece of camera film where it had this transparent haze to it.
After this point, I just kept trying to get back to that vibration I was operating at. As an analogy, once you tune your radio to the right energetic channel, it gets much easier to get back to that place once after finding the correct channel. In the earlier stages I felt it was like trying to turn the dial wildly to try and get anything but just getting static. It was super frustrating. But if you keep at it, you can get it eventually.
It's definitely something that as someone with aphantasia, I had to basically fit those puzzle pieces together and keep trying to get that place of being in a trance to be able to perceive those energies. When you think about it, everything around us is just energy vibrating at different frequencies at the end of the day, which sounds super weird if you're unfamiliar with the concept. But, when you put something under a microscope, you see that everything is just moving rapidly. It's my personal belief that humans have all the tools they need to be able to see and read that energy, it just takes strengthening of certain skills and muscles to get there, even for people with aphantasia. This is why I believe even if you do have it you can overcome that obstacle, because it isn't so much about "visualizing" (which, for the average person, it's an easy way to explain what astral travel is), but about being able to open yourself up to decipher the energetic signals that are being sent your way.
So, meditation is definitely the first step in getting to a truly trance-like state, and this is going to be your best bet! Find meditation apps, a Youtube channel you like, or read books on different meditation tactics, or just try the tips I suggest above. Whatever you do, keep practicing, and eventually your third eye will slowly strengthen and start being able to interpret those signals for you!