My approach to design has always been holistic, meaning that the more information you can provide, the greater the chances that I can succeed in creating something that perfectly fits your needs.
As a general rule, information that I look for when looking at designs are:
Purpose
Audience
Content
Colours
Style (i.e., minimal, retro, etc…)
Examples if you have some (screenshots, links, etc…)
Backstory: This is where I get a lot of my inspiration for designs, especially if you’re not sure what you want. A backstory could include the reasons why you need the design, or a backstory on yourself, which could include some meaningful symbols/colours to you.