If you are going to look good, you probably have to give nature a helping shove before you can convincingly wear female clothes. To begin to get the necessary curves, you need to add to the chest region, remove from the waist and give yourself some hips. The latter two are less important, but what fun is a bra without.. (complete this sentence in not more than twenty words)
Convincing breasts can be achiveved with silicone 'lumps' that were originally devised for medical purposes but now can be used as bra fillers, or with special glue, bra-less. There are (to my knowledge) no artifical breasts that feel 'right' and look real at the same time. Silicone breasts will warm to your skin and move properly under clothes, but won't look real. Cheaper breast forms may look real (hand painted nipples, no less), but won't move or flex with the rest of you, which can cause problems, unless you plan to stand in for a shop window dummy. A much cheaper option, that can still give a relatively good shape and movement is to take some white balloons, put one inside another (for strength) and fill the inside one with water from the tap to the desired size. Put these in a properly fitting underwired bra and you'll look perfectly reasonable.
If you have a beer-gut, now is the time to re-read that bit about looking after yourself. If on the other hand, your tummy does not spill over your belt, you can give yourself a reasonable (or even unreasonable) waist with a waist clincher. Like a sawn-off corset, these clip together at the front and lace up in complicated ways at the back. Pull the laces tight and inches will be taken off your waist. Take it gently though, starting off with a little reduction then waiting twenty minutes before tightening a bit more. Remember that you should be able to feel your legs and breathe. If you can afford it, a corset can provide a one-stop replacement for a whole load of complex underwear, and help with those curves as well.
Wider hips require more unusual help (padding made only for trannies, as we're the only lot who need it). Special 'pants' can be bought that have built in padding to achieve child-bearing hips. I must admit I haven't tried these as they're expensive and look rather complicated if you need to go to the toilet in a hurry.
Heels can also help, as they make your calf muscles tighten, which gives a prettier shape to your legs. However, overdoing it will make you look like a lamp-post and walk like a duck - besides being unsuitable for all but the wildest parties.
And finally, a nice head of hair. Buy a wig. Better still, buy five. Wigs should last a couple of years with good care and utterly transform you. Longer hair can frame your face nicely and a fringe is a much better than a receeding hair-line. Hairdressers will tell you to choose a colour that is a shade or two lighter than your own, and this will certainly look the most normal. However, (hurray) the fashion world says that dying your hair is cool, so there's less wrong with some fairly artificial colours - so long as you realise that every woman in the world will notice you first as someone who dyes their hair, and then as someone who's wearing a wig. If you're going clubbing, this doesn't matter, but if you're shopping for your loaf of bread in the local supermarket it can cause problems. Most wig shops are quite cool about trannies, especially if you're polite and phone ahead for an appointment. If you go to a shop, you can get some expert advice and avoid making a very costly mistake.