I teach 4-5 year olds in a Montessori public school. We use sandpaper letters to teach the sounds and do 5 letters at a time(4 consonants and a vowel) You can get tactile letters at teacher stores. The sandpaper is there, so you can show the child the way to trace the letter and they can see, hear and feel the letter. We don't teach the letter name; we teach only the sound. We also have objects that start with each of the letters the child is learning.
This is how our lesson goes. The letters are laid out on a rug.
Trace the first letter and say "This is aaaa(sound) Now you trace it and say the sound."
Continue with all the letters.
Ask the child to "Show me
aaa. Show me buh", etc. If they get it wrong, correct them gently by reminding them, "This is buh."
Have the child say the name of the object and match it to its beginning letter.
After they have matched all the objects, so the show me part again. If they seem to be doing well with this, go to "What is this sound?" while pointing to a letter.
We also have little letter books that have pictures of things that start with each letter. The kids really like the books and the "work" as well. Six of my nine 4 year olds are reading at this point, and the other three should be there by the end of the school year.
Marsha