Yes, this has been my challenge. Too many wonderful projects and ideas to manifest!
Like Leif, I have learned to prioritize. I judge by what really juices me most because that's the creative energy that is pushing to come forth. I love when the process of creating just spills over like a cool, swiftly flowing stream! I find that I don't have to think about the project very hard at all and everything unfolds beautifully almost on its own. It doesn't feel like work.
When it begins to take more laborious effort and I feel too much of a strain, I stop.
At least, this is what works for me!