Nothing new here, really, but it struck me again this morning as I was practising just how important it is to always listen, always make the best sound I possibly can when practising. It doesn't matter whether I'm playing scales or Bach, trying to make a lip trill work or doing range-stretching exercises, the most important thing is to use a good sound.
Now, that doesn't always mean the tone colour will be conventionally beautiful. There are times when it's appropriate to make an 'ugly' sound for effect. But it has to be on purpose... it should be for effect, not because I've stopped thinking about it.
I did tell you it was nothing new.