A pattern is only a pattern when something repeats

It may be a single shot or combination of shots you're looking to execute on a regular basis and it's known in tennis as a pattern of play, relentlessly drilled in on the practice court so as to become second nature on the match court.

There are generic patterns that we see across the game and more personal individualised patterns that depend largely on a player's strengths/weaknesses and game style.

Laying down your patterns in a match brings about an increase in confidence by reducing the potential anxiety brought on by the uncertainty of what to do/shot to play next and generally means that you are in a position to dictate terms.  Knowledge of your opponent's favourite patters helps you to counter them with the objective of blunting their strengths.

An example of a generic pattern would be using the 'double opener' when serving.  A right-hander from the deuce court might look to slide the serve out wide and then attack the space into the open court.   Individualising this pattern could be linked to whether you attack the space with an early backhand or get around the ball to use an inside-out forehand (this of course could be determined by the speed of the opponent's return).  

What are your 'go to' patterns of play?  Can you write them down?  Are you drilling them consistently on the practice court so they become second nature on the match court?