Valleyrie has made good suggestions, just want to chime in with a few of my own!
You can use make-up to contour your features to look more masculine. Dabbing a bit of concealer on your lips to make them pale also helps. YouTube has plenty of make-up videos! Just type Female-to-Male make-up, FTM Make up or even what I typed, Masculine make up and you'll get tons of videos
If you want to look gender-neutral, just omit the stubble part that they may do in the videos or if you like, make the contouring more subtle.
Wearing baggy clothes will definitely help as anything form-fitting will give away your curves. There isn't anything work-out related that will lessen your curves per-say but if you are already at a healthy weight, doing strength training can help to tone your body overall. If curves really bother you and you'd consider surgery as an option, there is a Mansculpture technique where a surgeon uses liposuction to shift your fat from/to different areas to create a masculine body figure; however, I don't know if they do it as a stand-alone option, it sounds like they will only do it if you get top surgery as well since it's cheaper to get both done at once than separately.
