In case your buttons or videos appear unstable even though you hold the device steady, make sure you follow the following guidelines:
Avoid placing your buttons
- on top of empty spaces,
- on top of repetitive or symmetric patterns, or
- on pages where the distinct elements are not distributed uniformly,
e.g. on one side only.
If your page contains a significant amount of blank space, it might not be suitable for reliable recognition and stable AR tracking.
In case there is considerable uncertainty for the visual recognition algorithm where to place your content, this might result in decreased stability and a "shaky" appearance.
In general, it is better to place your content directly on top of details on the page than on empty areas. If this cannot be avoided, try to place your content as close as possible to areas of detail on your page.
Please also make sure to follow the guidelines provided here: http://www.layar.com/documentation/browser/howtos/layar-vision-doc/page-best-practices/ before you decide on the type of pages to use in your campaign.