I also like to listen to music, neo soul to be exact. it gets my head right.
Another one is writing things down as they come to me, whether is on an old receipt ,a napkin or some scrap paper.
Sometime I meditate, it causes such a calming effect and it helps relieve my anxiety that is a by product of my diagnosed PTSD. It also gives me prospective and insight, which helps with my writing.
Writing shitty first, second and third drafts to get some prospective is a huge help in narrowing down what to writ about.
Getting some one to read after me then make changes.