BUM, one of the best ways to help yourself play in a more relaxed way is to move your practice time to a lower tension time. If I come home from work and try to get a half an hour in before dinner, that is exactly what happens - I SQUEEZE something into an unnatural time frame. I spend that time with my kids instead. Then we have dinner together and then I go open end into my practice time. The same on the weekends that I don't have gigs. Take care of the family first and then reward myself with a great relaxed practice session!