Relax before the test. Nice deep breaths in, holding it and out. Controlled breathing just as you would under an attack situation.
When doing the test, it's all about thrust! So a quick and deep breath in and then as hard as you can out. It will likely give you a little tickly cough for a few seconds afterwards.
Use a peakflow meter, you can pick them up for a few pounds on the internet now. You want to be aiming at blowing around 400-450 for a positive pass
