For these cuties, I used the same technique for the knit hat as I did for the gingerbread men sweaters. All details and information for the tutorial I followed is here-https://www.iftheovenmittfits.com/2018/12/24/iced-gingerbread-men-cookies/
I used my go to royal icing recipe.
The blue icing and white icing is flood consistency. The red and pink icing is medium stiff consistency-similar to toothpaste. The orange and black are also toothpaste consistency. For the knit hat, I used tip 14. Everything else was tip 2 or 3. 🙂