I have worked with all sorts of animals and have done a lot of rescue work. I've learned a lot of little tips to help myself and others avoid bad situations. Here's one others might find useful:
When someone is handing you a nervous small dog you are handling the first time, have them pass the dog to you butt first. I have been told, "She will never let you hold her without biting you!" Using my butt first technique, I floored the people who said it when the dog was calm and subdued in my arms. Why I believe this works is because in the dog world, the dog who gets his butt sniffed is the submitting dog. The sniffer is dominate. By presenting the dog rearend first, the first person is clearly communicating to the dog to submit to the second person. Animals can be unpredictable and I am not an expert. Use at your own risk. However, I have never been bitten by dogs previously known to bite using this method.