I can't really stress enough that, well - you and me?
<disco> We're animals, baby. </disco>
All of us are, really, and if you're looking to interact with any kind of animal you would do very, very well to learn about animal training. I'll probably write about this in a more general sense in the future, but for today, let's specifically talk about Touch Training:
Usually, one of the first things you do when training an animal - any animal - is acclimate it to its handler's touch. A properly touch-trained animal should be perfectly comfortable being manipulated by its handler and makes a whole host of training and care tasks both easier for the trainer and less stressful for the animal being trained.
To give an example, imagine an animal has sustained a minor injury - a dog picked up a thorn, say. Even a friendly and tame animal won't often want to be picked up and physically handled while it's in pain. It may resist being handled or even - at no fault of its own - bite or scratch in a bid to protect itself. Taking the time to touch train your pet will make sure that you can borrow its paw, pluck the thorn, and treat it's wound without risking further harm to yourself or the poor animal. Because the animal is used to being handled - because it trusts you - what would normally be a stressful experience becomes a comforting one.
The usual method for touch training is to consistently and gently manipulate the animal in the presence of positive stimuli. Sometimes, touching isn't an option to start with and you need to start with just being allowed near or around your subject. A good way to start this process is to be around the animal to provide it something positive that it needs, like food when it's hungry or warmth when it's cold. Over time, you can move from sitting near to lightly touching, and so on.
In the longer term, you should be able to systematically manipulate every part of the animal's body as though you were inspecting it, rewarding the animal as needed to encourage submission to the procedure. The purpose here is to make sure that it is comfortable with all kinds of handling and that it positively associates being physically manipulated. Ideally, flopping over and offering itself to be touched should be a positive experience for the animal being trained.
Physical contact and affection are themselves positive stimuli for many creatures you might want to train as a pet or service animal. In addition to making the process of touch training easier, this has the pleasant side effect of making the training practically self-reinforcing. Routine activities such as grooming, cuddling, and play will reinforce the connection between the handler's touch and Good Things in the mind of the animal being trained and help form a bond between the animal and its handler. Just make sure that you don't unwittingly countertrain the behaviour, and it should persist without much effort.
Particular to humans, initial training can be made remarkably simpler by just explaining the process to a willing participant and encouraging active cooperation. Training tools like visualisation or roleplay can be used to train cognitive behaviours directly and can facilitate extremely rapid and robust training, with skilled handlers showing adequately touch-trained subjects in less than a day.
