When teaching Arabic Calligraphy the teacher should ensure

the following points form the basis of his/her class:

1- Provide students with two specific goals:

General Goal – such as improve overall Arabic Calligraphy practice and confidence.
Specific Goal – such as learning how to write the letter “Alef” e.g. , and its position inside the Arabic word).

2- Familiarize student with the first letter Alif and present a word or sentence where it appears in different forms (beg, middle, end)

3- Ensure adequate supply of materials is available for the class such as:

Lesson Structure

Beginning the class with an Arabic sentence and describe its meaning to the students, (the sentence may be a Quranic verse, Hadith , old Arabic Sayings or Maxims).
Describing each letter and how to commence it
Asking them general questions on what was described to ensure that whether they have acquired information or not.
Students will write the sentence in their notebooks according to what was shown and described.
There will be a follow-up on their handwritings and guidance Whilst writing
Marks upon finished work
A similar sentence to write as homework to continue practice

Note that, these steps will depend on their ability of reading and writing Arabic letters and sentences that they learned from The KG stages.
Children will be learnt 2 Calligraphy styles ( Naskh and Reqaa ) as they are easy to learn specially in first years of education . But the other scripts can be learnt to the elder