I wish I could write an inspirational answer to this question, because it’s ripe for a motivation expert to make money from. Alas, I will not be inspirational, only honest.
I had a very productive summer on both the writing and the work fronts. I paced myself so that my work didn’t fall due at the last minute. From this, I learned what motivates me.

First, boredom motivates me. There’s only so much scrolling on the Internet I can stand without being bored. I don’t like being bored. I could have slept all that time, I suppose, because I don’t find sleep boring; however, day sleeping is not good for me. That left me with needing something to do, and work and writing helped.
Second, flow motivates me. I get flow from productive writing. Not so much from putting together classes; designing course sites and planning lessons doesn’t promote that seamless experience. I want to experience flow, so it’s motivating.
Third, blocking out time motivates me. I had whole days to waste all summer and work that I could do later. Instead, I told myself daily, “I will do three chapters first, then follow that up with writing time.” I put the less motivational classwork first. I scheduled everything in-between my intern visits (which broke up the monotony of having the same classwork daily).
There are some things, however, that I find so unmotivating that I avoid them. Housework is one of these things. I seem so overwhelmed trying to clean a cluttered house that I just break down. Our house is messy and cluttered as a result. Not dirty, just messy and cluttered. I think I will not be motivated for that until my husband and I decide to tackle the clutter together.
We can use the following professionally recommended strategies: 1) Break it down into smaller tasks; 2) Do the hardest stuff first; 3) Reward ourselves; 4) Quit if we’re not into the task after 15 minutes. That last part is the challenging one: I am never into housework. Is anyone?
I am obviously not a motivational expert, because I have not conquered my house. I hate the thought of the house taking away my precious writing time. So I hope my readers got something out of this anyhow.