The phrase "The less I try the better I do" certainly applies to the golf swing. Often times my students return from their first PGA Tour event describing the player's swings as "effortless" and yet they create amazing distance.
The reason is speed comes from flexibility and flexibility means lack of muscle tension. The more speed you desire the more important flexibility becomes. Try to throw a baseball with a tense, stiff arm or try to run fast with stiffened legs. You get the idea...
For golfers, tension is their biggest enemy, and flexibility is their greatest ally. At address your arms should be completely tension free and remain this way until the swing is completed. When you arms are tension free the feeling is transmitted to the entire body. This allows you to swing the club with a feeling of effortlessness.
Most players think the harder they swing the farther the ball will go. NOTHING COULD BE FARTHER FROM THE TRUTH! Trying to hit the ball harder creates tension. Remember, tense muscles do not move fast - they are a speed killer. Speed comes from flexibility and flexibility means lack of muscle tension.
Next time you practice or play focus on making relaxed swings with a more relaxed grip pressure. Ensure you can feel the clubhead in your hands throughout the entire swing. You will hit straighter, more solid and longer shots.