Building up a collection of images and examples to show the designer will great assist them in providing you with a design to your taste. Above all though it will give you time to dwell and revisit an idea with a partner who may well have a different view! 

At the very least it can help stimulate a healthy debate by giving you options to choose from. A smartphone can be an incredibly useful tool as no matter where you are you can take a snap and digitally record an interesting feature or design you come across. 

At the end of this process you will need to review your choices to prioritise your ideas.