It is very important that you know the techniques involved if you want to improve your tennis forehand even more.  Knowing the techniques correctly will let you win more tennis match since the tennis forehand can be considered as the most reliable shot.  When doing the service, your swing needs to be exaggerated and powerful. This is one prerequisite in doing the tennis forehand technique properly.  Most importantly, it would be much better for your tennis forehand technique if there is someone at the other side of the court to return your service or shots because you can then constantly practice the tennis forehand technique.  You can also try to assess your shots.