The Public Service Announcement of the weekend is on the topic of tonguing. There is a lot of dogma on tonguing out there to cut through which seems to me at least in part to be driven by false perceptions and what sounds good on paper rather than on reality.
The longer I teach the more I feel firmly that there is no one way to tongue and that approaches to tonguing actually vary widely in the horn playing community. How you tongue will likely be significantly different than they way your friends or colleagues tongue, even if the results sound practically identical. It is an important topic as on the horn tonguing is really a big key to everything, especially accuracy. I have two major suggestions as you sort out tonguing in your teaching and playing.
1. Look at the older printed sources that are pretty independent from the line of thought given by Farkas and try to understand that they have equally valid points of view. Two quotes I like a lot as they open up new ways of thinking about it all are this one from Milan Yancich,
I then demonstrate different kinds of articulation: placing the tongue out very far between the teeth for heavy, marcato or hammered playing; placing it behind the upper teeth for legato playing; putting to tongue to the roof of the mouth to give an even more legato articulation; and finally placing the tip of the tongue against the lower teeth, using the flat of the tongue against the roof of the mouth to produce even another attack. The student then understands that the tongue, very much like the bow on a stringed instrument, can be used for many different types of articulation.
and this one from Anton Horner, which is the closest description I can find in print of the way I actually tongue,
Attack each note with your tongue as though you had a small hair or tiny piece of thread on the end of your tongue and wanted to force it out of your mouth.
2. Be very wary of dogmatic tonguing advice from players of other brass instruments. Realize that the way a teacher of any other brass instrument than the horn says to tongue is probably different than we would employ on the horn, and they also have no concept of how drastically different tonguing is on the horn in different ranges.
The way we need to tongue is in general different than trumpet or trombone but probably closest to that employed on the tuba. Back in April I posted,
One aside I want to explore further this summer; I found that I can articulate a tuba. The tongue stroke I use for low horn transfers over pretty well. When I play trombone or trumpet, however, my default tonguing sounds overly harsh, even blatty. There is something about the slower response of the horn and tuba that requires a more active tongue stroke.
A side point being though that on the F horn in the upper range my default tonguing also sounds overly harsh. I suspect that years of double horn playing has led to some subtle choices in this regard, or that perhaps the Bb horn is simply more forgiving. On the F horn in the higher range and on the natural horn I have to very consciously use a more gentle tongue stroke more up on the gums than where I default to.
As to what to practice, nothing really beats Kopprash. For more suggestions as to what to play this post is a good place to start.
As a final thought, I know that the way I tongue is considered wrong by some teachers. Yet, I know I get high level results (check out my solo CDs!) and that quite a number of players approach it as I do. I have puzzled about this for years. In the end, the important thing to remind yourself of is that the result is what matters — if it sounds right it is right. If you are a teacher be aware of the variations of tonguing methods, treating everyone as a unique individual toward achieving the best results possible.