How do I design a book cover template in Photoshop?

I can't find anything on the internet that tells me how to design a book cover template. All I get is downloading templates. The self publishing company I picked allows the author to design their own cover template. I need a good answer please.How do I design a book cover template in Photoshop?
First of all you need to know what the size of your printed book will be, including the width of the spine.





Make your Photoshop document to this size (change the pixels to cm or mm settings for ease of use) and allow a few mm extra all round for 'bleed'.





You will also need to know what resolution they would like you to use (typically around 300dpi) and set colour mode to CMYK for printing processes.





Look at some book covers to get ideas for how you want your design to look, eg placing of pictures and text and check out any online tutorials if you need help with achieving a particular effect.





Place each element on a layer of its own so you can move things independently whilst you are working (keep this file in .psd format).





When you are happy with your design you can merge all visible layers but make sure you save this file as a copy so you retain your layered file in case you decide on further changes.