What a coincidence.. My name is Danielle, too, and I`m trying out for the ATSSB All-Region band.
I tried out for All-Region last year, and got fourth chair Wind Ensemble, which advanced me to Area, where I got 8th, which was four chairs too low to advance me to State. If my scales had sounded better, I`m almost sure I would have made it.
This year, I`m a senior, and I`m trying to make every one of my scales sound perfect. I agree with the second poster, start slow, and try doing different patterns with the chromatic scale. Instead of playing eighth notes, play dotted eighth note patterns, or play every note three times in a triplet pattern. I also recommend going all the way up the chromatic scale, bottom C to top C, on just whole notes to work on your tone quality.
Also, this has nothing to do with finger technique, but it is an amazing aid for air/tone control. I`m sure you`ve heard of enharmonics. On each of your very low notes, you can play 5 and sometimes 6 notes on the same fingering. For example, if you finger a low D, you can play that note, a regular D, an A, a high D, and and F#. Work on this slowly until you can get it into quarter or eighth note patterns, and you`ll find the high notes MUCH easier to play. Hope this helps, and good luck - hope to see you at State this year!
-Dani