Stop trying to come up with ideas and start with the technical side of your project. Switching to a new task is a great way to get your creative juices flowing, and thinking about the technical side of things will give you a little insight into your working process and help you see new options.
All you need to do is create a list of all the steps involved in what you are working on, down to the littlest details. Then create a flowchart from where you start your project, your action steps, the decisions you have to make, and where you need to stop.
When you are done with your flowchart you should feel the creative juices flowing back, not to mention you now have a tutorial for your project that you could use in the future.
If you really want to challenge yourself create your list of steps starting from the end and working your way back to the beginning.
Working on the technical side of your project is a great way to get inspired.
Have you ever listed all the steps involved in creating your art?