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When you create a post, on the right of the button POST, you have a line entry Rewards, with 3 possible choices:

  • Power Up 100%
  • Default (50%/50%)
  • Decline Payout

To decline payout, just select "Decline Payout" before clicking on POST.

Doing so, proves you don't have a bias to exploit the resources of Steem power.

I am not at all sure why you should.