When you practice with a metronome, you build a stronger internal beat (sense of time). A strong sense of time will allow you to perform better with others and perform rhythms more accurately. Here are some steps to follow when practicing with a metronome.
Always write down the tempo you end a practice session in your practice journal or on the piece of music (in pencil). Doing this will let you know what tempo to start with on your next practice session. Remember the "3 times perfectly" rule. You might feel a rush to speed up your tempo, but this will only cause you to practice mistakes.
All good metronomes (link to best metronome blog) will allow you to turn on subdivisions (eighth notes, triplets, and sixteenth notes). A subdivision is a smaller part of the beat. For example, eighth notes are a subdivision of a quarter note. A good rule of thumb is to set your metronome beat to the smallest subdivision in the section you're practicing. If the passage has sixteenth notes, turn on your metronome's sixteenth-note subdivision.
This would also be true if the section has dotted eighth-sixteenth note rhythms. You might want to use subdivisions when the tempo is very slow. It can be hard to stay with the metronome when the beats are far apart. Using subdivisions allows you to feel the space between the beats, making it easier to stay in time.
Unfortunately, you won't be able to perform with a metronome, so it is important to learn to play in tempo without it. After you have practiced with the use of the metronome at your goal tempo, it is time to practice relying on your own internal beat. Here are some steps to help you not wean off the metronome.
Doing this regularly will help you become less reliant on the metronome.