How to create WordPress theme previews for themeforest?

Hello Everybody,
I have create a wordpress theme with a good control panel.Now i want to sell it on themeforest. but before this i want to make a beautiful display for the viewers, how i can make these different beautiful screenshots for my theme?

Screenshots or active demos of the theme?

Just screenshots, like in mobile, ipad, macbook. and also of different angles.

You can find loads of these device mockups on GraphicRiver then just load the theme and use a screen capture tool or browser plugin and add these to the mock up

Thanks charlie4282.
I had searched this for too much time. you saved my time for future wasting.

There are lot of ipad, macbook mockup template out there, totally free, just google it :grin: