As much as people want to "think outside the box", it really is very difficult to think of an idea or a viewpoint that you wouldn't naturally think of.
As recent Wall Street Journal article describes how Campbell Soup is looking outside for ideas (MarketingProf's summary here). This same approach that a gold mining company took is described in detail, including the great results, in Mavericks at Work.
If this is a good, successful idea, how are you doing it? Scenarios could include asking a Scrum Coach to review your work (your product backlog, sprint backlogs, user stories), setting aside time regularly to read on the topics you're involved in at work (Scrum, QA, automation, tools, the business sector you are in), and setting up periodic meeting-of-the-minds, whether trusted colleagues, a conference or seminar.
I have not once regretted the time I have set aside for any of these. There are always new ideas that I never would have considered that were immediately application to situations and challenges that I was facing. Yet I still don't make it the priority that reflects the value it is.
How about you - where do your ideas come from? How do make sure you put things in place that help you at what you do?