I have experience in teaching little children with flash cards, I start with the letters with fatha until the child will recognise them then I start joining three letters together to make simple words with fatha until they are very familiar to the child then we do the same with Dhamma, kasra and sukoun.
When the child will finish all the basic sounds we move to double haraka which is mudood.
After that the child will be able to read words and simple sentences.
Later we move on to shadda and other rules for the beginning of the AL (shamsiyya and qamariya)
And more and more to learn until the child will feel confident to read any word I give to him.
After that we can start some grammar lessons.