Taking the dog for a walk, is good for many situations including stress, fresh air and different surrounding. Can't beat it!
Also can be done at night which to non uk users is known as dogging, watching people having sex in cars whilst walking your dog, not that i would do it
Water is effective for me.It has a way of calming me and letting my creative juices flow.Bathing, Diving, Swimming or Gym sweat generally does it.
However I think the requisite to generate a good idea is to always have an inquisitive open mind.
By drinking beer, beer made the pyramids, started the economy, was called the gift of the gods in ancient times, how could you not want to hook up with such a powerful source?