Autumn was feral and was at the shelter I volunteer at, so they had already made some attempts to tame her, however she was still very aggressive towards people.
To begin with I just let her out of her cage and ignored her (keeping an eye on my legs, she has a tendency to bite and scratch) let her do her own thing while I did mine. Eventually she stopped swiping at me, I still couldn't touch her, but it was a start. Then I started paying attention to her, playing with a wand toy, touching her back with a long handled brush etc.
Then one day she hopped up beside me on the chair in there. I just let her sit beside me, didn't touch her and she stayed there for about half an hour. The next time she did it, I tried petting her and she allowed it, for a few strokes before hiding back in her cage. Slowly she allowed a few more, then she would actually come up to me as soon as I came into the room.
I took her home not long after and she just seemed to settle a lot. I wouldn't advise putting your face near her's or touching her tummy, but just by spending time with her she gets calmer each week. She now sleeps on the bed with me and doesn't try biting my toes.
She is definitely food orientated, whatever she is doing that I want her to stop, I take her away from and when she has calmed down and sat down I give her a treat, now she doesn't bother fighting with the boys, apart from the territory spat she has going with Bumper for space on the bed which is also beginning to settle.http://amby.com/cat_site/feral.html
has some great links to articles on how to tame ferals and deal with problems that typically arise with 'tamed' ferals as well as body language to watch out for to know what is working and what makes them scared or aggressive.