I printed the letters (sized 650) out 4 to a page, cut apart, and then sat down at the computer with my kids to pick out pictures online that began with the right sound for each letter. This way they have a personal attachment to the letters and pictures (for example: space rainbows, monster motorcycle, princesses, and sword). I printed the pictures out, cut them, attached to the appropriate letter, wrote the lower case letter in the corner of each, and then laminated. They are now hung on the wall where both children can easily see.
My goal is to have letter time every day on this wall where we practice for as long as their attention span will allow. There is definite progress and I am very excited. My sweet boy is so excited to read by himself and is anxious to learn his letters. This of course makes the process a bit easier. Kudos to those who already have 4-year-olds who know their letters and/or can read!!