Use at most 4 colors, even better if you use 3 colors.
Use a repeated symmetric design so that it is suited for more formats.
Use the uploaded logo.
The uploaded examples are not to be copied as it is copyrighted material.
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.