All decisions are ultimately emotional (see Emotional Intelligence by Daniel Goleman and Descartes’ Error by Antonio Damasio). Your unconscious mind, which notices more than you are consciously aware of, communicates with you via feelings (see The Gift Of Fear by Gavin de Becker). If you don’t feel 100% positive about an important decision, this may be a sign that you have missed something important.
As well as checking your feelings, keep your feelings in check! If you are in the grip of a really strong emotion (positive or negative) it pretty much shuts down the thinking part of your brain. “Strong emotions make us stupid” – neuroscientist Joseph LeDoux in The Emotional Brain. To detach (or “dissociate” in the NLP jargon) from the emotion, imagine floating up above it.