I want to also, again, note -- HRT, HRT, HRT, HRT! Makes a difference. From a lot of experience with others, including myself, it can be very difficult to know if someone is gonna pass if they haven't really started HRT or transition yet. On that note, I know of some x-dressers with a lot of experience, not on hormones, who can pass, especially with a lot of work... but it takes work. Like, knowing what to wear and make up, etc. It's not an over-night thing, same thing with transitioning.
As for myself, I've just become incredibly lazy with doing much of anything 'cause after 4 years of HRT, I can get away walking around without make up, doing my hair, or doing much of anything. o_0 I'm actually surprised some days at how I don't get noticed. But, for the first year, couple of years, I had to work more at my appearance, clothing, and so on -- I got better over time, and so will you.
I've seen some amazing transformations, from people who you would never think they could pass before they were on HRT... but, amazing things happen on HRT + time. Passing is also not just looks and voice, but social cues, body language, and all that stuff. It takes time, but you'll get there.
You have positive attributes already, and that's great -- work with them. Starting with long hair is nice, 'cause at least you're not starting with short hair or a buzz cut or no hair. You're slim, so you can work with that. Make up can be learned (feel free to experiment, spend time in a mirror and play around, remove make up, and then try another look). Feel free to walk into a store and buy some make up (try a few cheaper colors to experiment with first -- find something that works, and then if you wanna go more expensive). A lot of boys buy make up, especially ones in the goth/metal/emo/etc communities... it's not really weird anymore. Not like the first time I bought eyeliner in the late '80s in a small, uber Christian town where the cashier said, "You're a boy, you can't buy this." I said it was for an "art project" and after weird looks, she sold it to me. I then later got beat up by school for wearing it, but that's another story.
These days, people really don't care. Same if you walk in and buy girl clothes. *shrugs* I just walked into the mall and bought it, even tried it on, and besides a few weird looks, most people didn't care. If the mall is a bit much, there's a lot of other small shops -- especially goth/metal/emo shops that will gladly take your money, let you try on clothes, and even give you tips on what looks good. Or, even go to a thrift store. Grab some clothes, go into the change room, and try them on.
You'd be surprised at how many people don't care, or actually will give you good advice. If you really feel uncomfortable, use the old stand-by story that it's for some crazy party.
Just be glad I'm not around... girls starting out transitioning don't like to be around me 'cause I've got a reputation for saying "lets go for coffee at the mall," and then dragging them into a woman's store with me and getting them to try on stuff, then going to the MAC store (or any make-up store, or even drug store) and putting make up on the (or getting the make-up artist to do that). I guess I'm a bit intense for some ppl's likings. o_0
Make-up stores are great, 'cause you get someone who knows make up and 9 times out of 10 the make-up girl or boy artist will love putting make-up on you and giving you tons of tips. Seriously, go into one of those stores and do it. Or, go with a girl you know, get some cheap make up together, then go home and let her experiment on you. Trust me, you'll both have tons of fun.
So, have fun with transition. Experiment. Do all kinds of things. Experimenting is the best (and funnest) way, in my opinion, to go about with make up, hair, clothes, etc. You'll also get a good make-up and fashion sense pretty quickly.
I guess I'm a bit head-on 'cause I was pretty determined. I won't lie and say it was easy at first. I actually first went out shopping with a cross-dresser via friend of a friend (I knew no one else in the trans community), and she dragged me to a huge, very busy store, walked with me down the isle, told me to pick a few things, then we went into line to buy them and she vanished, leaving me in line with woman's underwear. o_0 She was watching from afar to see if I would actually continue to stand in the long line and actually buy the clothes. I was scared and looking around. But, I did it. Best thing I ever did to start my transition. Then, we went to the next store, since I had underwear, it was time to find clothes. Again, picking clothes, and then I went by myself to the change room to ask if I could try the clothes on. I did it. Again, best (and scariest) thing I did. After that, it was putting on those clothes and taking public transit... I believe that I was frozen the whole time. But, I did it.
Every time after that, it got easier and easier to go out, get clothes, get make up, get all of those things, and also go out FT.
