Staffy's are often too smart to respond to "typical" training. They'll figure things out and they need a reason to do things. NILIF - you've seen Serena's posts about it probably - Nothing In Life Is Free, has some real plusses with dogs like Terriers, and I'd also recommend checking out the Monks of New Skete training books and videos.
Then, there's always my little method that gets a lot of strange looks, head shaking and disbelief . . . I talk to mine. I explain to them what I want and why, usually nose to snout, always in a quiet, low voice and very calmly. Of course, you'd better be very sure of your dog before you stick your nose that close, and it's only going to work if you've established a tight, tight loving bond and a great deal of understanding and rapport. And your dog has to be used to you just talking to him/her on a routine basis. Then you have to get used to all the looks you get from other people. (lol)