It's absolutely astounding what you can accomplish when you work on an important project at least a little bit every day. Just putting a short session every day, and occasionally letting inspiration take you further, means you can accomplish damn near anything.
Working regardless of the inspiration means that things take shape and start growing. Rarely do projects that aren't abandoned fail. They might not reach the magnitude or scale you'd hoped for, but any project that's consistently nurtured and acted on usually produces something of value.
Daily action. It's incredibly what it does. If you've got a big project or dream that's stalled out, the answer is really simple.
Stop and ask yourself: Am I working on this every day?
Then, fix that.