Have more than one thing going

Creative projects have developmental cycles of maturity. The energy, mindset, and approach required at one point in the cycle is different than what's required at other points in the cycle. The beginning is loose, sketchy, fast. The end polishing is slow, specific, detailed. And yet our own energy and the forces within ourselves don't always match what's required—when you've been working for a long time on small, slow details, it can wear you out, and make you eager for a change in environment and context (Shift stances to refresh yourself), eager to do something fast and loose to relieve your muscles and mind from too much consistency in one place (Balance intermittent continuing with medium intensity semi-consistency)

Therefore, have more than one thing going! If you're writing something that's almost finished and are working on small details and edits, start something new right away. As you finish one painting, start another one before you finish. As you wrap up one software update, start getting the next one sketched out. That way, if you're interested in writing lots of things or making lots of things, your energy will have a place to go that matches its current state. This isn't a way to constantly work or never rest, but it is a way to Let momentum carry you and keep your creative time flowing in a cycle.