It is nearly always easier to hit the ball back directly along the arc where it came from. It is also easier to hit over the middle of the net.
It takes more energy and skill to place the ball exactly where you want it.
Practice with a partner and, rather than just hitting the ball back-- try practicing the various shots. Hit cross-court backhands, then cross-cout forehands, then down the line shots, and so on.
In hitting any shot, you have to conciously determine where you want to hit the ball, position yourself correctly, and stroke THROUGH the ball in line with where you want it to go.
Practice, practice,practice-- Good luck,
B