Once you have a clear idea of who you’re designing for we would advise you to gather inspiration for your design. This can be found online, in magazines or out in the street.
Research similar businesses, this will give you an idea of how they represent themselves, you don’t agree with their approach. This inspiration doesn’t have to have a direct link to what you are designing, it may just be designs/images/colours you like (and don’t like!).
It’s a useful exercise that can help you find a common theme and create a clear picture of the look and feel you want to aim for.