I have asthma, and take Becotide (Beclomethasone Dipropionate, as mentioned) once a day, and Bricanyl (Terbutaline Sulphate, that one purports to be) when I need it as I'm allergic to Ventolin (Salbutamol). I cut down my Becotide use from twice a day after talking to the doctor, and have found that's okay, but if I get wheezy or have an attack, I double the dose of Becotide for the length of time it takes to recover, and half that time again (again, the doctor's advice). This seems to keep everything in check, and the only times my asthma makes itself known is if I run or if I walk quickly up a steep hill.

Interestingly, recent studies have apparently shown that "alternative" treatments such as acupuncture etc. don't help asthma (the most recent place I read this was the Sunday Times, I think, so I can't claim to have a watertight source) BUT that one thing that does help is yoga, which seems logical since it promotes controlled breathing and relaxation.
I have also heard of people being advised to take up wind instruments to help strengthen the lungs and control breathing. I don't know how well this works though, but I had a go on Ella's flute and was bent double, breathless and red-faced within 10 seconds.