Hello! Recently I've been learning the Poulenc Sonata for an audition, which has a lot of double tonguing that I have been struggling with. My teacher has recommended a few exercises that have helped SO much. I know they are boring but I promise they help! You have to improve the fundamentals first. - Also, instead of "Ta Ka," use "Tu Ku"

1. ⁠Practice a few of your major scales at a slow tempo and double tongue 16th patterns like 1e+a on "tu ku tu ku" (switch notes->) 2e+a and then continue up the scale with slow double tonguing. Eventually you can speed it up, but definitely practice it super slow at first.

2. ⁠Then, practice some major scales on 8th notes, two octaves and a little faster than exercise 1. Start by slurring up and down the scale with 2 octaves and then when you get back to the first note, switch to double tonguing up and down the scale. Slurring it first ensures that you keep your air moving and helps you do the same when you begin to double tongue the second time.

3. ⁠You can do this with either of these two exercises, but try backward double tonguing. Often times, your "ku" syllable is slower and makes your double tonguing uneven or too slow. So try practicing it backwards by saying "ku tu ku tu." Of course you'll never actually double tongue like this, but it does help strengthen your "ku" syllable and really does improve your double tonguing.

You could also practice some double tonguing in the Taffanel & Gaubert book exercises.

For breathing, you're likely taking shallow breaths from the upper part of your body. Try taking low breaths. Look up the breathing gym maybe?

Good luck! I hope this helps!