As you look to identify areas of improvement in a process, one of the best places to start is by looking at 'waste'.
"There is nothing so useless as doing efficiently that which should not be done at all."
- Peter F. Drucker
For a full list of questions to ask yourself as you look to find improvements, take a look at this list from the University of New Hampshire's 'Phase 5: Design Recommended Future State Process' - laid out under the 'How' section.
For more information on taking a Gemba Walk, take a look at A Guide to Successful Gemba Walks by KaiNexus.