Someone asked me this week:

What advice could you give me as an aspiring student to become a teacher?
Here is my reply:
Teaching can be a very rewarding career, but it’s often a tough way to make a living.  I struggled for years and years.  Most of my friends who taught with me are still struggling financially.  
On the other hand, it is very rewarding to spend time studying and talking about something you love (languages, in my case) and sharing that love with students.  Unfortunately, most students aren’t interested… but, some are.   And, it’s fun when you find them.
If you really want to teach, I’d give this advice:
Learn to speak well in public.  Join Toastmasters if you have a club in your town.  Watch TED talks and learn to imitate the speakers.
Master your field.  Spend several hours a day studying what it is you want to share with the world.
Blog your way through the experience.  Post reviews of books you read.  You can post them on (and, read the reviews of others).  There are many ways to post these days. is still free (I think).  You could post blogs and reviews there. 
Don’t worry about readers and followers and all that.  People may not find your blog for a while.  That’s okay.   Practice being consistent.   The trick is to get started.  
I am slowly writing a book on this topic.   Your email reminds me that I need to keep going.  
I am slowly posting what I am writing on my blog.   Just go to my blog and read any post titled “How to teach online”.