Congratulations on your soon-to-be retirement!
I am sure it is well-earned and wish you all the best.
First, do no harm.
Make certain you have the ability to help each student build a solid foundation.
I have been very fortunate to have had very good music teachers. Over the years, each new teacher has added to my progress and development as a musician without spending valuable time making me start anew to reform poor technique, practice habits etc.The last thing any teacher should be doing is passing on bad habits.
If you are doing it right, teaching can be pretty hard work! I have tried doing it myself: group and private guitar lessons. I routinely revert to just performing as a source of supplemental retirement income. I find it so much easier to "go solo" than having to be responsible for the nurture, care and feeding of budding musicians. There is probably a teaching gene that I did not inherit.
Perhaps take a few lessons from an experienced guitar teacher with a view toward fine tuning your own pedogogical principles?
Perhaps volunteer your services at a local organization as a prelude to opening your teaching studio? This could be a great way to select, tryout and develop new teaching materials/methods. It could provide you with valuable local contacts as well, if necessary.
Keep performing as much as possible! The most frequent inquiry at many a gig is, "Do you give lessons?"
I will be watching this thread with much interest as the true guitar teachers weigh in.