I have an app which helps the user to design a full screen sized postcard. The result is exactly what the user sees on the screen.
Because a lot of users scan things in an F pattern, I assume that the top and left side of full screen represents the most valuable "real estate". in this case, the postcard title.
This makes me pose the following design question - do I design so that the controls panel is the most obvious part, on the left side screen (easier to find tools the user needs, traditional). OR do I design so that the product's (postcard) top and left side are most easily accessible ( tools panel on the right, as in the screenshot)?
An example of the controls panel on the bottom and right: