Worksheets that make you shade in things with the letter "B" or match B to a picture of a balloon.
Grades K/1: Make an alphabet book, with an option to choose a theme based on interests: dinosaurs, nature, Star Wars, etc. Challenge children to design the whole book. You can have each child create one, or have children work in teams. Or you can have the whole class work together, each producing pages for a class book. Arrange to go to another class to read your book to them. Leave the book out as an option for silent reading.
Grades 2-5: Still take time to read one-on-one with students, to make sure they are fluent. If they are not, give them direct instruction in sound letter connections and patterns that they are missing. Encourage students to read a loud to the class, to continue to practice this fluency with pronouncing words. Reading out loud involves many skills, and asking comprehension questions as part of it, can be too much at once.