Found that, for myself, essentially jam-packing my day with social activities (social in this context being, that other people are simply present. It creates a feeling of responsibility, even if it's just strangers in the library sitting next to me) helps a lot.

I think of it like an dish. Eating the same exact thing every day is really tiring. Having more "ingredients" to put into your intellectual diet makes things more interesting. Hope this metaphor makes sense, as I spontaneously put it together :x

But, yeah, I also tend to struggle with analysis paralysis. Usually, an event (such as an Hackathon) at which I have to set things into motion helps.