Panoramas
A panorama can be the initial window to your application, it can help to surface top level pieces of information with the aim of getting users interested in your content and to encourage them to discover more.
You can decide for yourself how many panes you can place into your panorama but you need to be careful not to push too much information. There are two reasons for this, firstly, because the user scrolls round the panoramas in a loop, if there are too many panes they can get lost within the narrative of your application and forget when they’ve come back round to the start. Secondly, there can be a hit on performance if the application is trying to display too much information within one panorama.

An excellent reference point for best practice on panorama implementation is the phone itself. Take a look at the way content is browsed and presented in the people and music hubs, these are great visual references.

It is possible to place an image in the background of your panorama but be thoughtful about the image you choose to place there. Make sure it is contextually relevant to the content of your application and even consider if you need an image at all.
You can place a list into your panorama but be careful that it doesn’t get too long, again this can be confusing and cause performance issues. Consider having a smaller list of items and then a ‘more’ button if you need to show users a lot of content.
Finally, panoramas are not always the solution to the problem. They can be visually appealing and playful but once a user is past the initial surprise and delight of your application, you need to ensure that it is usable.
For a detailed look at the layout within a panorama, take a look at this great article titled, ‘Designing hubs, good examples using the panoramic control‘ over on the Windows Phone blog.