Rearranging the letters of 'anagram writer' (Anagrams) gives:
Arrange (mar) wit.
(by Kevin Sheldrick by hand) (2015) (pending approval)
Rare, warm giant.
(by Heather Anne Downs using Anagram Genius) (2011) (pending approval)
Other related anagrams without their own page:
"What is an anagram" -> "A harming Satan. Aw!" (by Josiah Winslow) (2011) (pending approval)
"A manically presage William Shakespeare" -> "I am a especially weakish anagram speller." (by Jim Banholzer) (2018) (pending approval)
"Arif Fachrudin - Ponorogo - Jawa Timur - Indonesia" -> "Contoh anagram dia jadi isu ne WN RI or FPI or UFO." (by Arif Fachrudin by hand) (2011) (pending approval)
"Arif Fachrudin - Ponorogo - Jawa Timur - Indonesia" -> "Roso Jiwo Rogo Fidin Nur Fidihana nate pacarmu." (by Arif Fachrudin by hand) (2011) (pending approval)