Transgender male to female, 18, wondering what makes someone (me) look boyish vs feminine? (photos)

I agree with you.  Longer hair will do a lot for you.  You have nice eyes, lips, arched brows, and cheeks.  I think the only thing you mind consider coming around to is a rhinoplasty focused on the tip mostly.

You already have a lot of feminine features including smooth skin, full cheeks, and a short upper lip. The main thing that stands out to me is the brow bone. While not too prominent, it still casts a small shadow on your eyes. You would be surprised at how much setting back the forehead a few millimeters will help. 
Other than that, you may want to consider narrowing and shortening the chin and jaw and making the lips more full. 
Once your hair is longer, these few things so go a long way in helping you look more feminine but very natural. 
Best of luck to you,
Sarah Saxon, MD

Hello,Overall, you have a fairly feminine face. Unless there is something that bothers you about your face, I don't see too many give-away "masculine" features. It is difficult to see from the photos if you have a prominent Adam's Apple. If so, that is a very masculine feature and having that taken down can create a more feminine appearance quickly.The best way to determine what could be done to further feminize your face is to get a plastic surgery consult. This way, your surgeon can go through the various options and procedures with you. There is really nothing better than an in-person exam to see what would suit you best. 
Various options include contouring the forehead to make it flatter, narrowing the jaw and chin, raising the eyebrows, shaving the Adam's apple, and rhinoplasty. These things can be combined in various order to achieve your desired result and a plastic surgeon familiar with facial feminization surgeries will be able to go through those things with you. 
I wish you all the best on your journey,
Dr. Blagg
Austin, TX