At the end of my list of links to reviews of trans and/or non-binary literature by trans and/or non-binary reviewers, there is a resource list. I pulled out most of it as a separate resource post for writers, and then added to it. All of these essays and resources were written/created by trans and/or non-binary writers.
General Essays On Writing Trans &/or Non-Binary Fiction
Dear Cisgender People Who Write, Publish, and Read Trans Books by Constance Augusta Zaber, a trans woman writer and critic
Writing Better Trans Characters by Cheryl Morgan, a trans woman writer
Should I or Shouldn’t I? On Writing Trans Narratives Respectfully by John Jacobson, a non-binary genderqeer writer
How to Write Trans Characters by Everett Maroon, a trans man writer
Being Trans is a Lot Like Being a Book by Austin Chant, a trans man writer
10 Helpful Tips from a Trans Woman for Making a Trans Woman Super Hero by Mey Rude, a trans woman writer and editor
Ways to Intro that a Char is Trans (& Pitfalls to Avoid) by Xan West, a trans stone butch/genderqueer writer (a twitter workshop focused on romance, but useful for other genres)
Writing Non-Binary Characters – A Primer by Cecil Wilde, a non-binary trans writer.
Trans Tropes That Have Got to Go (as Told by Trans Readers) by Avery, a neutrois/agender writer and reviewer
Deadnames in Fiction by Ana Mardoll, a non-binary trans writer.
On Trans and/or Non-Binary Children’s Literature
Evaluating Transgender Picture Books; Calling for Better Ones by Kyle Lukoff, a trans librarian and author
Second Trans on the Moon by Kyle Lukoff, a trans librarian and author
On Trans and/or Non-Binary YA
The Acceptance Narrative in Trans YA by Vee, a non-binary trans blogger
The Hero’s Journey in Trans YA by Vee, a non-binary trans blogger
Trans Representation in YA Is Only the Beginning by Everett Maroon, a trans man writer
On Trans and/or Non-Binary SFF
Gender, Sex, and Sexuality in SF: A Conversation between Polenth Blake, a non-binary writer, and Bogi Takács, an agender trans writer and reviewer
Changing Images of Trans People in Science Fiction and Fantasy Literature by Cheryl Morgan, a trans woman writer
Beyond 101: a conversation about trans and/or non-binary SFF with Katherine Cross, Margaret Killjoy, Ana Mardoll, K.M. Szpara, and Vanessa Rose Phin.
On Trans and/or Non-Binary Erotica and Romance
Talking Trans Erotica with Tobi Hill-Meyer by Jetta Rae. Tobi Hill-Meyer is a genderqueer trans woman writer, editor, actor and filmmaker. Jetta Rae is a trans woman writer and editor.
You and Me Could Write a Trans Romance, a Hopeless Romantic podcast episode with Austin Chant, Sam Schooler and Amanda Jean.
On Comparisons: Writing Trans Characters in Same-Gender Romance by Austin Chant, a trans man writer.
On obligatory scenes in trans romance by Austin Chant, a trans man writer.
On Internalizing the Cis Gaze When Thinking About Sex and Relationships (discusses this issue both in communities and in trans romance and erotica), by Xan West, a trans stone butch/genderqueer writer
On Trans &/or Non-Binary Poetry
Waves Breaking, a podcast showcasing the talents of transgender, genderqueer and other gender variant poets, hosted by Avren Keating, a non-binary poet and artist.