Play the first note of a C chromatic scale below the treble clef staff. Play each pitch of the scale with the following pattern: half note, half note followed by a whole note. Take a breath for four beats and continue the same pattern on the next pitch in the scale. Continue ascending until you can no longer play any higher. Do not remove your lips from the mouthpiece in between pitches and breathe only through your nose.
Play lip slurs to help develop your flexibility. Start on a C below the staff and slur to the C an octave above by tightening the muscles in your stomach while simultaneously doubling the tension in your lips. With practice you will learn the proper amount of tension to get the best sound.
Practice tonguing exercises to increase the clarity of your articulations and improve your tone. Start on C below the staff and play sixteenth notes at quarter note equals 60 beats per minute. Gradually increase the speed until you can play sixteenth notes at 120 beats per minute. Make sure the tip of your tongue hits the position between the roof of your mouth and your teeth for a proper articulation.