To get your Dyson curls to stay in begin with damp hair and then use the right barrel size for your particular hair type.
Also apply mousse or leave in conditioner and section your hair into small parts and use the cool shot feature to set each of your hair curls.
Avoid touching the hair until the hair is completely dry.
And for very straight hair you should use a smaller barrel for tighter curls and also ensure the hair is fully dry before you release the curl.
Make sure your hair is damp and not soaking wet and apply a heat protectant or other styling hair product for curls.
Then divide the hair into small sections.
Also smaller barrels create tighter hair curls.
While curling your hair you should use the hot setting to form the hair curl and then finish it off with a cool shot to set the curls in place.
Allow your hair to fully dry before you style the hair further or touch the curls.
And avoid touching or brushing your curls once the curls are set.