This is a loaded question and it will really pertain to several different factors. How often do you play? How often do you break strings? What racquet do you use? What is your swing style? Do you hit with a lot of spin? Manufacturers will often give you suggestions on what tension and strings you should use, but it’s just a starting point. Strings are really meant to enhance your playing abilities. So you want to find a string that works well with your game and can be adjusted to different tensions. Higher string tensions will often result in more control, while lower string tensions will often result in more power. Just remember that the tension and string you use will always affect the way you play. You want to make sure you’re getting the proper effects out of that string, so you can remain confident. The current trend with stiffer strings (polyester, kevlar, etc.) is to string them lower (45-50 pounds), while natural gut or multifilament strings can be strung tighter (55-65 pounds) and maintain solid comfort.