I second the idea of making books together, if your children are interested Use photographs, your children's drawings, etc. It can be about experiences you've had as a family, fascinating facts learned, dreams for the future, etc. Have your children dictate the stories while you model saying the words slowly and writing the sounds. Link the sounds to known words (i.e., "M-e-x-i-c-o, that starts just like 'mom' with a letter m, M-e-x-i-c-o, I hear 'ex' like the exit sign, etc.")
Would he be interested in having you create his own word bank. Have you read any of Sylvia Ashton Warner's work on the key word approach to reading? With the key word approach you ask children what words they want to learn and put their words on cards, doing just one or two words a day. They keep their word cards in their own special box. At first you can spread out the words and ask them to find certain words, as identifying and finding are easier tasks than reading the word on their own. Eventually you can add a verb such as "loves," "likes," "wants," and your child can make their own sentence with their name, the verb card, and their special key words. Rather than teaching your child the phonics and then teaching them how to read words using the phonics, you are helping them develop a love of learning words, then connecting it to the phonics ("Look 'monster' and 'mom' both start with M! Can you hear how they start the same?") Some children respond better to learning to read in this way as it makes it more meaningful for them
Another idea would be to create a family alphabet book or an alphabet book for each child, if the child is interested in learning letters. Use big pages and have a page for each letter. Write both the uppercase and lowercase letters on the pages. Put family photographs and names on the correct alphabet page and then have fun finding pictures or drawing pictures for other letters. Work on one letter at a time or add to it periodically throughout the year. Model excitement of discovering about letters and sounds, "Wow, this is such a cool seashell! Let's take a picture of it and put it on the S page of our alphabet book"
Children learn so much from us modeling our interests. Do you model reading and writing for your children? Not just reading, but actually talking about what you read or write. Maybe keep a journal, write in front of them, talk about why you want to write down your thoughts and experiences. Stop in the middle of your own reading to share interesting ideas with your children. Model your own excitement for reading and writing.