Nearly everyone who stops making progress is still practicing. They're just practicing in a way that can't produce progress, and the fix is in how the time is spent rather than how much of it there is.
Short and daily beats long and weekly
Twenty minutes six days a week does more than two hours on a Sunday, and it's not close. Physical skills consolidate between sessions, so six consolidations beat one. If a week has gone badly, ten minutes still counts and it keeps the habit alive.
What a session should contain
- A few minutes of tone. Long notes, listening. Boring, and the single highest return activity available to a woodwind player.
- Something technical. A scale or an exercise, slowly, with attention on the thing that's not working.
- The hard bar. Not the whole piece, just the two bars in it that keep failing. Slow enough to play correctly, then a little faster, then correctly again.
- Something you enjoy. Finish by playing something you can already play. This is not indulgence. It's the reason you come back tomorrow.
The rule that changes everything
If you can't play it correctly, you're playing it too fast. Playing a passage wrong twenty times teaches your hands to play it wrong. Slow enough to be right, every time, is the whole method, and almost nobody does it without being told.
Practice with a metronome, sometimes
Not always, since that gets joyless. But rhythm problems are invisible without one, and most players who think they have a technique problem have a rhythm problem.
For parents listening from the next room
Good practice sounds repetitive and slow. Bad practice sounds like the whole piece, played through at speed, with the same mistake in the same place each time. If you hear the second one, the useful question is "what part are you working on" rather than "have you practiced".
What to work on each week is what a lesson is for. Lengths and rates are on the pricing page, and if you're just starting, what happens in a first lesson covers the beginning.