Why waste precious time at the grocery store when you could multitask and not only shop but also brainstorm while you shop? I read this article about keeping your creative juices flowing by analyzing your surroundings, even if it means just looking at color combinations and critiquing. The more exposure to designs that are both effective and not can only help when it comes to creating designs of your own whether it be for print or web.

http://www.howdesign.com/design-creativity/idea-generating-tips/unlikelycreativetime