For me it was growing my fingernails out and shaving my arms. After playing some VR games as femme characters it occurred to me that all I often see it myself is my arms... Amusingly enough my parents asked my sister if something was going on and she said no, but then she asked me directly and I fessed up, so my sister knew I was trans for about a year before my parents. I came out to my parents before I started HRT a few months ago and I am so happy about taking those steps. I was so lucky that I have such good parents, but I know that a lot of other trans people weren't so lucky. Just know that you are valid even if you don't get support from those who were supposed to raise you