These are things that have helped me…Please feel free to make more specific to you when possible.
1) Take a class in something that isn’t improvisation—cooking, shooting, whatever.
2) Spend a weekend with non-improv friends or have a long phone conversation with an old friend who doesn’t know you as an improvisr
3) Give yourself a non-improv challenge: don’t use your cellphone for a day or learn a new language or a musical instrument
4) See a foreign or silent film
5) Get a colonoscopy (everyone should)
6) Get a game-changing haircut
7) Pull a Holly Hunter and let yourself have a good cry every morning for a week
8) Get laid proper
9) Spend an afternoon with a pre-school class; or see if you can read them a story you loved when you were a child. Make it interactive if possible.
10) If you always wear something to shows, wear something different with a different cut/feel/texture