We are always fighting human nature when playing a point in a tennis match. It is natural to try to disguise your shot so the opponent does not know what you are going to do.
The problem is that even if you fool your opponent, if the shot is not hit well, you are likely to let them back into the point. A shot hit well, exactly where your opponent thinks it is going, will be difficult for them to reply offensively to. This is especially true if you can control the direction and hit the ball cleanly.
This idea is much more effective than continuously trying to adjust your shot because you are trying to fool them. Hitting that unpredictable shot looks really good if you can pull it off, but more often than not, the shot turns out to be not what was intended—either the direction or the quality of the shot suffers.
Try focusing on a good solid hit to a specific area on the court and pay less attention to your opponent and what they are expecting. This is likely to give you the best result, the majority of the time in an actual point situation.