At the school I'm at we do 'Sound of the Week' each Tuesday.
There are multiple activities for each letter that the school has collected over the years and I try and add to that collection when I can! The foundation for each letter every week that we have are the sound drawer, the sandpaper letter, the ASL card for the letter, and an initial sound booklet. We also have an animal alphabet book as well as a clever rhyming book (Ants on an Apple) that we use at circle.
We also put out a simple art project (in this picture there's both a stamping and a pin pushing of items that start with 's') , as well as a handwriting activity for the older children.