Custom menu screenshots

Hi,

I’ve decided I’d like to add title screen images to my menus and need a bit of help. I tried downloading these through Retroarch but they don’t display, however looking through the downloaded folder I’d prefer to create my own over the ones provided.

I’m using custom menus for the systems, is there any way to add code to the notepad file (or a separate file) to show a screenshot with each menu entry? If so can you provide an example of how the file is set out with a couple of games so I know how to do this? Going through instructions on here is a bit difficult to get my head around but a sample usually really helps.

Thanks