One fun way to teach letter sounds is to have a child sort objects by beginning sounds. The letter sound for x can be taught by ending sound since the real sound for x is not found at the beginning of words.
Toys and other small objects can be collected and used for letter sound sorting and practice.
Lakeshore Learning sells Alphabet Sounds Teaching Tubs .
Here's a link to the teaching guide available for these tubs. If you don't want to buy the tubs, you can get ideas to make your own tubs. I suggest using ziplock bags or recycled plastic containers to collect objects that start with different letter sounds.