First thing - confidence
Learn to blend in and dress your age. This will help to keep unwanted attention from yourself.
When I first started out as a full time female, i dressed very gender neutral in public. I would wear a pair of jeans with long oversized top, the top would be a little feminine. At this time I already had long hair and pierced ears as during my cross dressing days I hated wearing wigs so I grew my hair, my ears, well I wanted to wear earrings and it ok for men to have long hair and pierced ears. Before my breasts became noticeable,I would stuff my bra.. nothing too big as i wanted to blend, I wanted my breasts to be noticeable, but forgettable. If you walked past me, you might notice me, but after 10 seconds you would forget about me. My friend told me once, if i wore my hair loose and a pair of hoop earrings, i looked more female than male during that time. I will admit, I never had very strong masculine features in my face.. so when hormones feminized me, i passed quite easily. I was never called, so if someone did clock me, they never said anything.
As the effects of hormones feminized me, i became more and more braver and I my dress sense went from gender neutral to more female/
To blend, you need to dress for the occasion, for example a trip to the grocery store, women don't generally dress up for that.. so if you arrive in 5inch heels, a dress that is more suited for a club and you face plastered with makeup, people will notice you and if you don't pass well, you will be noticed...