No seriously, get up right now and go for a walk. We'll wait. If walking isn't an option, any moderate, repetitive exercise can provide similar benefits.
Freewriting--getting words down on paper without structure or limits--can unlock your creativity in unexpected ways.
It's easy to do: just grab a notebook or a blank word document, set a timer for ten or fifteen minutes, and write steadily until your time is up.
In his excellent book On Writing, Stephen King wrote, "If you don't have time to read, you don't have the time (or the tools) to write. Simple as that." Great writing can inspire you to new heights.
When you want to get some serious work done, turn off the TV, lock your phone in a drawer (in another room, if necessary). You'll be amazed at the ideas that emerge once you give yourself a little peace and quiet.
Observe and Record
Go out and spend twenty or thirty minutes watching people. Observe how they speak, the gestures they make, the clothes they wear. Make up little stories about them and their lives--give them names if you want to--and write down your thoughts and observations in a notebook.