All I can add is that focusing on fighting/avoiding tension at all costs is one of the root reasons why it appears. We end up playing with the fear of it showing up. The more we try to avoid it, the worse it gets.
Prof Fabra says to welcome and embrace the tension. It is there because your brain has already released the adrenalin to bring it about nanoseconds before you attempt a note. If you accept and even embrace the tension and don't judge it negatively, it will gradually decrease because it is not important to you anymore.Really, the best person to explain it to you fully, Guitarist, is Prof Fabra himself!
