You would use it like the word 'wear'.
He is going to wear a white shirt tomorrow. = He will adorn a white shirt tomorrow.
She will wear a cluster of flowers in her hair at the wedding = She will adorn a cluster of flowers in her hair at the wedding.
You can also use it in the place of 'dressed'.
She dressed herself in pink every day. = She adorned herself in pink every day.
He dressed the child in mismatched clothing. = He adorned the child in mismatched clothing.
I hope that helped you, love. :]