There are many sounds you can practise that will help your singing improve.
One great sound is “neighing” like a horse. You want to make the sound a bit witchy or nasty. The problem is, if you force the sound, you are actually causing constriction, which is not going to help at all. This is a sound you can practise everyday that should feel relaxed. It is not a loud sound. You want to practise this at a speech-level volume with thin folds (your head voice).
Some singers will be able to do this easily, others will not. If you have trouble singing in your high voice, then this may be difficult so go slowly. Simply do it everyday, as often as you can, and it will gradually start to become brighter, louder, edgier, and less breathy. This can’t be forced…it must be “experienced” regularly. This is a fabulous head voice workout.
If you are doing it correctly then you will be working the aryepiglottic sphincter muscles in your larynx. When the AES is narrowed, the voice becomes more intense and more resonant at certain frequencies. AES narrowing is also called twang.
Check me out here at www.soundcloud.com for an example.