Here are a few ideas I use in my own work..
I hope they can be benefitial to you.
*Try some new mediums
*Its ok not to know what you are doing sometimes, just play.
*Use smaller format to experiment
*Create an orderly space to work in:
depending upon your personality, either eliminate and clear space or add inspirational things around you in your work space.
*Honor the possibility of a season, or cycle ...