An authentic gay male character would be: sensitive but not effeminate, handsome but not full of himself, underrated by everyone around him, including his friends and family, yearning for something more than a superficial Grindr-like connection.
An authentic heterosexual female character would be: funny and charismatic, beautiful in an offbeat way, smart yet self-deprecating, fiercely intelligent and a devoted friend.
An authentic heterosexual male character would be: brash but secretly romantic, really smart and really funny, a goofball yet secretly brave and true.
An authentic lesbian character would be: neither butch nor femme yet with elements of both, smart in a way that sneaks up on people, creative and loving and independant, great with animals but not because she’s a lesbian.
An authentic transgender character would be any of the above, with the addition of not being surrounded by ignorant cisgender people asking the transgender person way too many, far too personal questions.