There is an amazing array of choices for which tennis racquet someone could use (and they change the models every year or two, to make things even more complicated); so, what are some of the factors to considering in picking the best one to play with?
Singles vs. Doubles – For me,the first consideration should be whether you play mostly singles or mostly doubles. For doubles players, the play is much quicker with shorter strokes; so a lighter racquet with more control is best. Singles players have the luxury of being able to take a longer swing; so they can use heavier racquet and frequently are looking for a little more power in their strokes.
Style of Play – Then, within all that is your personal style of play and physical abilities. Here, it is usually a good idea to talk with your local pro, who knows your game. They can give some good observations on how you really play (which is sometimes different from how you THINK you play) and which type of racquet best suits you.
Head Size – This is the very basic place to start in picking the racquet… should the square inches of the racquet head be traditional, mid-sized, or over-sized. Again, it comes down to what you play and how you play.
Balance and Weight – There are some fairly big differences in the overall weight of a tennis racquet, with some models being 25% or more lighter or heavier than others. Without getting too technical, racquets can also be: head heavy, head light, or balanced. This is where you can swing a racquet to get the ‘feel’ of it and get advice which suits you.
Power vs. Control – Manufacturers are now designing frames that theoretically give you either more power in your swing or more control in your strokes (some claim to give you both).
In addition to talking with your local pro, most shops and online services will let you test out different racquet frames. That is the best way to really get a feel for what best suits your game – before making an investment of $100 – $200.