Try a lower tension — less than 55 lbs. Most club player racquets we see are probably too tight — 60 lbs or more.
Even when a lower tension is requested, the local stringer will often think s/he “knows better” and will string closer to 60+. Or, their equipment is mis-calibrated.
Of course, the pros string tension depends on surface, temperature, humidity, the balls, etc. And, they have freshly strung frames for every match.
The image shows Nadal at 55 lbs and he probably takes one of the biggest if not the biggest swing at the ball.
Tennis is already expensive enough so we are always looking for durability in a tennis string without sacrificing too much power or control.
At this time, our favorite is the Ashaway Crossfire II.
1.30mm braided Aramid main string matched with a 1.30mm Synthetic Gut cross string creates a hybrid combination with maximum durability and toughness.
As the modern game evolves and you move above the USTA 5.x level, tennis is less and less about stroke mechanics and more and more a basic athletic struggle — crush the ball or be crushed.
Like basketball, baseball, football, etc., try to assume a solid, balanced athletic posture.
Try this back-straight, sit-down look.
Note also that your posture will affect your movement and stroke mechanics so be sure to work out the proper mechanics and timing using an athletic posture.
Not everyone has tree trunks for legs like the pros, but almost everyone can lower their center of gravity to a certain extent.
Do the arms, wrists, and hands look “loose and relaxed” to you?
This idea that the grip, wrists, and arms are very relaxed, sometimes described as “spaghetti like” I think is not only NOT helpful but can actually be harmful.
This concept can lead to a total misconception of how it all works, especially for the serve.
As I like to say though, “try it”. Do your dispersion study and see what works, then see if it is effective.