She asked for something home made, so he made a hair accesory with Altaria feathers, many hours spent in front of a staryutube tutorial with a glass of wine. There's also a postcard, and on the other side, written with Jaskier's fancy penmanship and red ink:

The winter solstice marks the shortest day,
with the promise of more light on the way.
There is an enchantment, a powerful source,
that keeps the wheel of nature on course.
Embrace the winter, so magic and cool,
And may you have a most blessed Yule!

~Your Secret Santa