Basically there are two ways to do this.
For simple parameterization, add a property to your data and data-bind the element property to your data property. There are lots of examples of this in the samples. The GoXamIntro document also talks about it.
You might find that you would prefer to define your own data-binding converter. There are examples of this too. We provide some commonly used converters, which are also used in the samples.
The other way to do this is to use separate DataTemplates. This makes the most sense when there are structural differences between the ways that you want a Part to appear. It can be easier to define two or three different simple DataTemplates instead of one very complex one. Simple templates are created faster too. You use data category names to select DataTemplates. Again this is introduced in GoXamIntro, and there are many examples of this in the samples.