I plan on teaching young German children (ages 3-10) English here in Germany. My goal is to use play and fun (with lots of games, creative work, singing, dancing, etc.) as my main methods for teaching the language. As most of the children will not know how to read and write, I want to rely heavily on interactive activities to teach English (with the 8-10 year olds I will be able to do more written work). One idea is to use "A Book a Month" and base my entire lesson plans for the month on this one book (children will meet once a week for 1 hour). For example, I could use "The Very Hungry Caterpillar", this is a book that most German children are very familiar with ("Die kleine Raupe Nimmersatt"). With this one book I could do lots of activities/creative work teaching about colors, numbers, foods, etc. I would pick a book for the subsequent month that builds on the previous month's book.
I have lots of creative ideas and they come mostly from my experiences with my own two children and my activities with the children in my sons' kindergarten. I am a German national living in Germany, but lived in the United States for more than 25 years (I have an M.A. in International Affairs, very useful

I plan on using the Montessori Method of teaching, combining this with a "native language" approach, that is, much the same way that they have learned/are learning their native language (using all their senses to learn). Does anyone have any advice for me before I start? What is the one thing that I should be aware of and incorporate into my lesson plans/activities. Of course, my activities with 3-4 year olds will be very different than those with the 8-10 year olds.
I greatly appreciate the opportunity to pick some experienced brains here!!
Greetings,
Apples4English