Needs to look professional, interesting and attention grabbing.
What to avoid
Unspecified
Files
Stock images
Client is not sure if they want stock images used in this contest.
Stock images are licensed photos and vector files. Please declare stock when you submit designs so that clients can pay for licenses.
Attachments
Unspecified
Contest deliverables
1 x Physical book cover
Winner of this contest
1 x Ebook cover
Final files
Layered vectors
AI
EPS
Screen quality
PNG
JPG
PSD
Fonts
If you use fonts that require a license, confirm with the client they're ok with it. For licensing reasons, it is better to provide your client with information on how to acquire the font rather than providing the actual files.