Serving is the most important part of scoring points in racquetball. So this is the area where you should practice the most. Your goal is to hit serves which are the most difficult for your opponent to return. So do not always hit your favorite serves all the time if they are not winning you points.
This video with Malia Bailey shows some drills which can be used to improve your serves. The idea of hitting targets is very useful, whether they are first bounce targets or targets on the front wall.
Many top players aim for exact targets on the front wall. With practice, you gain confidence in your front wall targets. Then during a match, you do not need to rely on “feel” to hit confident and accurate serves.
During practice games, try alternating serves to both corners of the court.