When you have many ideas in mind and don't know which one to go for, list all of them in front of you, then answer this question:
"Which one of these projects will make all the other ones easier to accomplish or even unnecessary to do?"
Then start with that one.
Try it out, you may be surprised. This question helps me focus and know what matters from what doesn't.
Remember: You can do anything, but not all at the same time.