One: wear exceedingly baggy clothing.
Two: wear hoodies, baggy hoodies. Even in summer.
Three: wear more than one shirt. baggy shirts.
Four: try to dress like a black gang banger. baggy. baggy.
Five: I don't know if I mentioned it, but baggy clothes could save you from hate crimes.
:-)
Six: working out won't be detrimental to your form. In fact, lower bodybuilding(leg training) helps balances out the weight from upper body to lower body. A bigger chest CAN possible help provide an excuse for the boobs. Despite what other members say, I close to live in the gyms and I know plenty of guys with saggy boobs that jiggle, but it's all muscle seeingas they bench in the 400 range.
A muscular chest will not effect breast growth. It will however, give you an excuse for boobs. "dude, I bench 225, of COURSE I gots boobies."
If you'd like some excellent advice on working out to match a MtF regimen, ask me. I need to write up a memo/FAQ and post it on here.
Seven: Wear something thick and form hugging underneath your BAGGY clothes, like a thick vest. This will add size to your shoulders and waist, making whatever breast development much less prominent.
As far as your hair and other appearances you have two choices: attempt your best at not being noticed whatsoever, or just deal with what people can think. Not many people can suspect something as far out as transsexualism and hormone therapy, so if you look like a girl you might be suspected of being gay but not of pursuing being female.
You can choose to keep your eyebrows bushy, hair short, face unshaved, or you can gradually start tweezing your eyebrows, shaving, and doing everything you can now to get into the feminine hygiene routine.