Using a video frame to accompany your video will give your Aura's more of a polished finish.
The way to build this frame is to create a PNG image with transparent elements in the middle in software such as Photoshop or GIMP (which is available for free online). Once this asset has been added to an Aura, position it in the Aurasma Studio so that your video can be seen within the transparent areas, as shown below.
Another tip is to select the 'initially hidden' box on this Overlay, and then request that it fade in after the video has faded in.
You could even use the 3D View tool inside the Aurasma Studio to bring your frame forward in 3D space so that pops off the page in 2.5D!