I don't know what I was thinking about first, but eventually it evolved into the ways cis people as well as some trans people have framed my transsexualism. This isn't a comprehensive list. It doesn't apply to everyone. This is a list of personal experiences that I have had as a white male trans man in the midwest. Most of them occurred pre-T. These are annoying experiences. Please do not repeat them with others.
1. Pointing out everything feminine about me as if you're helping me be a better man.
Unless we are explicitly asking for advice, just shut the fuck up. In my case, even some really good friends of mine seemed to have been just waiting for a time to inject that my earrings didn't help me pass or that my pendants were too big for a man to wear or that some behavior of mine came off as too feminine. These are things I was already fully aware of, and pointing them out only served to make me fully, deeply cognizant of the fact that my friends of all people were constantly pulling apart my gender expression.
2. Saying things like "Oh, I wouldn't date you, I'm gay."
Something I've never, ever, ever done: Asked a gay man out. No, really. If we were playing "Never Have I Ever" and you said "I have never asked a gay man for sex or a date," I would not drink because I have never done this. Even when I identified as a gay man myself. This is mostly because I don't expect gay men to be open to me. So wait... why are people constantly telling me about how undateable I allegedly am? Because when I made it clear that I was interested in men, the gay men "in the audience" would automatically, without any prompting, make it very clear that they weren't interested in me, usually using the frightfully transphobic excuse that they aren't interested "because they're gay."
Now, rejecting somebody's advances is absolutely your right for whatever reason you want. Not everybody has to be attracted to trans men. What I do demand, though, is some fucking respect. If you aren't interested in trans men, it isn't "because you're gay." We're men, you asshole.
You know what else? You don't even need to mention our trans status at all if one of us does hit on you and you aren't cool with that. Just say you aren't interested. You're talking about an issue that makes a lot of us really sensitive, and yet gay guys seem to ram through it like a fucking sledgehammer. Have some tact. Christ.
3. Referring to us using terminology almost exclusively used for our assigned sex.
When I first came out at college it was stunning how long it took for people to recognize that I wasn't heterosexual. One time somebody created one of the world's most disturbing queer games, "Guess My Kinsey Scale," and EVERYBODY defined me as a 0-2 even though they knew I was only interested in men at the time. This was a constant fight for me. One of the reasons giving up gay identity when I turned out to be bi was so difficult for me was because it was so fucking difficult to gain that distinction among a sea of well-meaning-but-ultimately-transphobic gays and lesbians.
Media and academia often have this same problem. Some of the first documentaries I saw on the subject of trans people referred to trans men as "transgendered females." The asinine autogynephilia explanation of transsexualism refers to straight trans women as "homosexual" and trans lesbians as "autogynephiles."
Don't do this shit. Seriously. Refer to us using terminology designed for our gender identities.
4. Assuming that being recognized as a third-gender is enough.
Unless the person you're talking to/about really is a non-binary-privileged gender, don't act as if we are some exotic in-between category. Some trans men and trans women do feel this way, but many of us don't.
When people tell me I should try to identify as genderqueer or something like that--considering I do not identify this way--what I hear is "I'm never gonna recognize you as fully male anyway so you might as well accept it." Bite your tongue.
5. Making comparisons to therianthropy or BIID without regard for trans peoples' feelings.
Therians believe they are somehow part non-human animal (spiritually, psychologically, or something like that) while BIID (body integrity identity disorder) is a condition in which a person feels as though an abled part of themselves should be disabled (for instance, somebody who feels like their legs are not supposed to be there). I maintain that these are both respectable conditions. I am a member of the wider therian community myself as well as a supporter of people with BIID.
Where things go wrong is with lack of evidence and lack of courtesy. Keep in mind that "what's next, transitioning into a dolphin?" is common snark against trans people (I mean, there was an awful South Park episode about that, right?), and so hearing comparisons like this can be a trigger for trans folk. In the case of BIID, making this comparison implies that people with physical disabilities have different psychologies/brain structures than abled people, which they don't.
The point is that although there are comparisons that can be made, they really need to be tactful and it's important to recognize that there are some really fundamental differences. Being a therian, for example, doesn't reflect on your ID, your birth certificate, or your records (because there is no field for "species"), it doesn't affect what bathrooms and public services you can use, and so forth.
6. People thinking they are savvy enough to use trans slurs.
"Oh, I see you're looking for more tr*****s on the Internet again!" One of my cis friends said that as she walked in and saw me browsing URNotAlone a few years ago. No, you really don't have the rapport with me to say that.
7. Talking about surgery.
I don't currently have the money for top surgery and that's a serious source of pain for me. I don't want bottom surgery and don't really like thinking about it. But people just love bringing up surgery plans, sometimes repeatedly (My dad almost has a little script he goes through that completely depersonalizes my body: "You're just going for the removal of the breasts and not the creation of the penis, correct?").
Most of the time when this is brought up by trans folk it's in the context of people asking very personal questions about what already is. "So, have you had the surgery yet?" And so forth. For me this manifests itself mostly with regard to my future plans because it's relatively well-known I haven't had any surgeries yet. I know that you're likely trying to act supportive, but all it really does is kick up my dysphoria and lack of self confidence. If you're talking about top surgery, all it does is remind me I have boobs. If you're talking about bottom surgery, all it does is remind me that there are a lot of people out there that don't consider what I have enough.
8. Constantly asking if my friends and partners are transgender, or if they know I am.
You know how many friends and partners I've talked about at home without my dad asking if they are transgender, usually in some offensive manner that I can't even begin to get him to understand is offensive ("So this is a guy who wants to be a girl, right?"). Zero. It's like a constant source of interest, as if the fact that I am trans means I must be in a friendship bubble with only other trans people.
The other, of course, is "Do they know?" The answer when it comes to me is this: If work friends, no. If school friends, probably. If close friends, yes. If partners, absolutely.
The reality, though, is that this is none of your business. You really don't need to know if my friends are transgender or not. And whether or not I let them know I am is my own business.
9. Lamenting my inability to have children or pressuring me to give birth while I still can.
No. No, no, no, no, no. Stop it. Christ. Stop telling me I should get eggs frozen, stop telling me I should consider going off hormones to give birth like Thomas Beatie, just stop it.
10. Bringing up Chaz Bono.
I like Chaz Bono. He has done a great deal for the trans community, and in many ways referencing him (such as in Dancing With The Stars) has been how my family has told me they support me when they are too embarrassed to outright say it.
But seriously. Chaz Bono is not shorthand for trans men. There's a limit.