Usually, before I begin writing some serious stuff, I would take a short nap of 15 mins. It really helps, especially when you are stressed and the deadline is nearing. When I finally sit to write, I would listen to soothing music while researching, in order to ease myself into the writing zone.
Whenever, I face a writer’s block, I take a break and chat up with colleagues, discuss mundane things, in the process resetting the flow of ideas. Later when I get back to writing, again I would ease into the zone through music.