Ok, wow, style was a BAD word choice on my part.
Let me clarify. One of the yudansha at my dojo uses atemi on every technique, including yokomen uchi kata atoshi. I prefer to skip the atemi at the beginning of this technique, concentrate on the blend, and then if necessary, move my hand from the shoulder to the carotid artery to drop uke, based on the level of resistance. Both are accurate and well within our style (yep, this is where this word goes) of Aikido. He also uses an atemi to the face when stepping hantai tenkan with a yokomen uchi, but he's a very big guy with a lot of reach. I am quite short, and if I were to use that atemi, I'd have to move back in to strike, and then back out to perform a technique and that feels awkward to me, so I usually go with something more along the lines of a kick to the knee or inside of the thigh instead. Both options are correct, but I have my personal preference, which is still slightly different. So my question, rephrased, is, At what point do I teach my personal preferences instead of teaching the same technique a few different ways?
As some have pointed out, around the shodan level, you don't "have your own personal style." And you're still very much in the "shu" stage of learning and development, as Peter addressed.
For reference, see https://en.wikipedia.org/wiki/Shuhari
In fact, part of your moving into the "ha" stage has very much to do with you working with the "shu" stage to present, as accurately as possible, the movements and approaches you've been taught by your head instructor and dojos approach.
Start with the movements you feel you understand the best, and start teaching them. All the while, working to emulate your teacher as closely as possible. This, in and of itself, will give you a completely different understanding of what your teacher has taught you. It will get the movements into a deeper level in your bones. And it will reinforce the teachings of your dojo to the students. It will then give you a different level of questions and investigations to go back to your head instructor with, and thereby drawing out even finer and more advanced points from them.
Even after 25 years of training, and even though I do a lot of aiki and IS-type training and teaching, I still - as a syllabus for aikido, up until around 2nd dan level - teach the rote movements of Nishio Aikido as I was taught by Nishio Sensei and his senior students.
Good luck with teaching the classes. It will open up a whole new level in your own learning.