the haircut and body language will help. you can get your haircut short, yes, but is it a masculine haircut made for your face shape? because i know when i wanted my hair shorter pre-t, etc. they would try to "feminine" up masculine haircuts, even though i didn't want that and it bugged me. same with body language. watch how guys around you walk, etc. usually arms out further, no swaying of hips, etc. try to copy them. even standing..i know it's more "feminine" to stand with your hands on your hips or like leaning to one side. it's the little things, honestly.
i know misgendering sucks, but it happens to all of us at one point or another. hell, i have been on T for two years and have facial hair and someone saw my mom and i walk into a store and said "hey ladies!" i was like but..facial hair??? deep voice??? flat chest??? sometimes it just happens. i think when you're further in your transition, it won't bug you so much but i can definitely see how it can now.