long tones
Long tones are the best way to improve your tone quality and stability on the trumpet. When playing long tones, it is advantageous to utilize a chromatic strobe tuner. The reason for this is so you can have a visual reference as to when you have locked in the desired pitch on your trumpet. Another way to develop your ear is to practice long tones with a drone tone (set this tone to the tonic or root note of the scale and keep it playing while you work through different notes). Playing with a drone tone allows you to hear what various intervals sound like in relationship to the root note. As you progress, try adding dynamics (crescendo/diminuendo) to your long tones so that you develop this "sensitive" aspect of your playing. Play through the entire chromatic scale with long tones if possible. Do not feel like you need to go directly into the next note. Take your time, catch your breath and reset your embouchure for every note. Remember that slow practice is the best practice. Figure that your quarter note should be about 60-72 beats per minute for this exercise.