Hi! I'd use songs adding the letters our sounds to practice in class, for example to practice the "L" sound, make them to repeat the sound and then to start naming words with that sound. You can also make them write or draw it while uttering the letter even they can use their bodies to shape it, you know children love all those types of activities that imply movement. Also you can show them the maner and place of articulation to foster pattern observation. Well this is all that came up in mi mind when I saw your question, hope it help you and also hope you get more answers. It is an interesting topic, isn't it? =)