I always review during the first month of school by reteaching letters and numbers. When I did a review of the alphabet with Avlyn, I noticed that there were a handful of letters she still struggled to recognize right away. These included: M, R, T, and W. After working with her, I realized that she is confusing M and W, and just needs a little practice with R and T.
I'm starting with M and W since I think she'll pick up R and T rather quickly. We have done coloring sheets, practiced writing M, printed out a letter M book that we read daily, and today we made a cereal M. You can find free letter printables at:DLTK
While I don't recommend wasting food, and know that a lot of homeschoolers are thrifty folks, using cereal or any other familiar food is fun for preschoolers. Not only does working with ceral or macaroni help teach letters, but it also helps with motor skills. If you really have trouble using food for projects, just use the crumbs that collect at the bottom of the cereal box or broken pieces of macaroni. Put the crumbs or pieces in a bowl, and let your child sprinkle them onto the letters. We did this with the little m, as you can see in the picture. You will need white glue for this, as a glue stick just won't adhere the cereal. Happy homeschooling!