I had my first ever private trumpet lesson earlier this evening from a good friend of mine with a very high level of talent and understanding of trumpeting, both natural and theoretical.
Today's first "food group" was tonguinig. Without giving away his work, he had some very good descriptions of tonguing and how it changes through the registers. He said he used it when he was training military band students and out of 200, 196 were able to use the technique, the remainder had other issues that kept them from using it, like one had a speech impediment.
I told him he needs to record his lessons and charge a nominal fee for them on the internet.
Interesting things I've learned. Tonguing greatly influences tone and if you tongue every note in the range equally, you're missing out.
Just like with powerlifting, anthropometry plays a big role in what works for a person. Copying a technique to exact detail more than likely won't wok, so some adaptation will be necessary.
Native English speakers have a particularly hard time using our tongues properly in that we, as a whole, tongue off the roofs of our mouths. Then we read Arban's, we see the syllable "tu" and don't know it isn't pronounced the same en franēais, so context is important.
Moral of the story: find a private instructor and get to brass tacks! We worked backwards to find my most efficient method and went from there, so I've been working harder than I should have. Now to get to working to practice the material.
Unrelated question: how do our British friends pronounce the surname "Taliaferro"? This came up later at my parents' and I said, "We'll settle this by axin mthe trumpetmasters."