Wash first. Use hot water and unscented detergent to remove any chemical smells. Wash masks at least daily.
Consider the straps. Try masks with ear loops and ones with straps to see what works best for your child and is most comfortable. Look into extenders that convert an ear-loop mask into one that a child is better able to tolerate.
If straps don’t work … sew buttons onto a headband or purchase one online to loop the ear-loops through.
Try distracting your kids … a drop of essential oils (mint or citrus to pep up), florals to calm. Use only therapeutic-grade essential oils.
Enlist their help. Remember, kids do best when they feel a sense of control. Ask for their suggestions on how to solve problems with their mask, and suggest masks with their favorite designs, characters, etc. on them.