For some children it is best to begin with very easy words, mostly three-letter consonant/vowel/consonant words like "hid" and "fix."
But there is NO reason to confine the words you give students to blend to such simple (and often boring) words.
In fact it can be counterproductive to go too slowly because you will lose the brighter, quicker learners.
With the Soundabet onboard, you can practice CVC words that include one or more digraphs. Words like "north" are easily decodable for kids who have the decided advantage of having learned the Soundabet.
There is no reason to confine yourself to one syllable words. I have found that a lot of kids in my class enjoy the delicious challenge and satisfaction of tackling multisyllablic words.
Here is what the pocket chart in my kindergarten classroom after a ten-minute session of blending words.
At the top are those easy three-letter CVC words. We used them as warm-ups.
Things got a lot more fun for them when I challenged them to read "complicated" "northern" and "california"—words that they read with ease and great pleasure.