Knowing what your strengths are and what shots you like to hit will help you identify your playing style. During a match you are often trying to play shots that you are most comfortable hitting, for example with an aggressive baseliner it's hitting big topspin forehands. You are also trying to find something that makes your opponent uncomfortable. For example, when playing against a counter puncher, it may be bringing that player to the net to volley.
Here are two examples of shot patterns (shot patterns make up the tactics you use for a specific tennis strategy) an aggressive baseliner may use when playing a counter puncher:
Crosscourt Rally, Then Down the Line

Recommended playing levels: 3.5 and above
Recommended playing styles: Aggressive Baseline; All Court; Counter Puncher
Crosscourt Rally, Then Drop Shot

Recommended levels: 3.5 and above
Recommended Styles: Aggressive Baseline; All Court; Counter Puncher