How do I get that full tone?
Well there are 5 factors involved in that.
1. The most important factor is AIR. The trumpet is a wind instrument. The effortless intake of a great deal of air is the start. The Effortless delivery of that air is the second half. Air is 70 - 90 % of the tone.
2. An Alert mind is vital inorder to always be on. That will always be in charge of what comes out. Never go through the motions. That is not only a waste of time, but it is also an insult to the artists and craftsmen who laid the groundwork for us to play quality instruments and beautiful music. Always be on.
3. Your ears are the next in importance. Not just hearing your own sound but also the sound of GREAT PLAYERS. We have to know what a great sound is to ever hope to get one.
4. A close aperture embouchure is vital to prevent that 5th grader airy sound from being our sound. Your lips should be touching. If the tone is a little bright draw the mouth corners in toward the center of your mouth. This will make an oval aperture and a pleasant sound.
5. Practice. Play everything with feeling and emotion. Even scales. If they are played right it can bring tears to your eyes. If they are played poorly they will bring tears to your eyes. ;-)