I love to work with variegated colored yarn and using a V-shape or a Chevron pattern, creates an interesting and fun design. You will find this in many of my knit.
Your children will look adorable and be snug and cozy in the Elf Caps. It is an old Folk pattern and has been around for a long time with various changes by each maker and so did I. I knew it under the name Teufels Muetze - Devils Cap; I took the liberty to change this as well!
I knit mine in garter stitch which has the advantage to stretch quite a bit, and therefore will "grow" with your children. It sits and stays on very well even without ties.
I wash all my knits by hand in warm water and mild detergent; hair shampoo works well too!
For sizing: small I consider up to 2 years, medium up to 4 and large will fit even an adult.