Ten of the friendliest CVC words in the language, one per box: cat, bed, pig, dog, sun, hat, hen, pin, box, and bus. Each drawing sits beside its word with the vowel hollowed out, c_t, b_d, p_g, and so on, with a e i o u printed under the title for reference.
The pictures here are unmistakable, a smiling sun, a plain box, a school bus, which matters more than it sounds. If a child cannot tell what the picture is, the phonics never starts. That makes this the one to hand a child working through missing vowels for the first time, before the pages with 15 or 21 words on them.