I use these in conjunction with National Geographic’s Reach for Reading first grade sight words.
To master their sight words, my lowest students work with these words each day. When they’re able to read the word without hesitation, I give them a check mark. When the word has five check marks, they’ve mastered the word, and they can move on!
You could give a sticker or some other prize when they master a word, but truly, their intrinsic motivation to master these words is usually enough!