Do your students have difficulty understanding the actual concepts of blending and segmenting sounds, even when you demonstrate. I find that many of my students do very well when learning letter names, and even letter sound correspondence (for nonsense word fluency). But, they have difficulty with tasks such as initial/final sound identification, and sound blending and segmenting.
I often use the actual letters in words to teach the concept and task of blending and segmenting, since in most cases, the kids understand that letters are used to make words. Once they are able to understand the concept through the support of the letters (phonics), they can more meaningfully practice phoneme blending, segmenting, and eventually addition, deletion, and substitution (all skills necessary as building blocks for reading).
In this activity, you have 52 words. Each word is represented by a card that contains a picture of the word with dashed lines to illustrate that the word exists in "parts" or "sounds." Each word also has a card with the picture, lines, and the letters that represent each sound in the word. The cards with the letters are to be used to TEACH the skill or task. The cards without the letters are to be used for practice once the student understands. I recommend laminating the pages, then cutting the cards apart along the dotted lines. The tactile activity of putting the words together and taking them apart also helps to solidify their understanding of segmenting and blending (like a puzzle). Each word in this activity is comprised of a consonant + vowel + consonant SOUND structure. Note, the CVC structure refers to the sounds in the word, not the letters (ex. "lamb" will be segmented as /l/ /a/ /m/ since the "b" is silent). I will add other activities in the future that target CVCV, CCVC, and CVCC blends.