Starting in the middle
When writing, finishing a sentence is easier than starting one.
A new sentence is a mini-blank page: A mini hill to climb up. Logically then, a way to start with momentum is to start mid-sentence.
Then you can finish that thought and have somewhere to go for the next one.
This was apparently Hemingway's way: He would end every session of writing mid-sentence so that every start was an easy downhill effort.