A flannel pajama set with stars is a cozy and fun choice for nighttime. Here are some features to look for:

1. Material: Choose a soft, brushed flannel for warmth and comfort.

2. Design: Look for sets with a classic button-up top and matching pants, both featuring star patterns in white or lighter shades against a navy background.

3. Fit: Consider whether you prefer a relaxed fit or something more tailored.

4. Details: Some sets may have additional details like pockets, contrast piping, or an elastic waistband for added comfort.