If your cat has feline asthma or other lung disease it might need inhaler therapy. I have documented how I trained my own cat to use the AeroKat inhalation chamber, get used to it, accept it, and keep coming back for it every day. I use clickertraining, which is explained in the video. It is not necessary but useful. I am not a professional cat trainer ;) I do know about animal training via the horses (Parelli Natural Horsemanship and clickertraining). My cat Beertje is a super cute Ragdoll, his colour is cream mitted. He is quite shy, very wary of new things, sounds, strange people (no visitors have ever seen him) and like most normal cats he likes to be around his owners, but does not enjoy being held or restrained by them. Cuddling is at his initiative, not ours. Shy cats need medication too, and when I was starting his training with the inhaler I did not find a good 'how to' video. The cats I saw made it look easy, which it wasn't for us, not at first. If I made a video now that he knows it we could make it look easy too :)
The firm behind AeroKat (Trudell) now has tutorial videos made by professionals:
Teach Any Cat AeroKat* 1: Creating Comfort    • Teach Any Cat AeroKat*  1: Creating ...  
Teach Any Cat AeroKat* 2: Building Confidence    • Teach Any Cat AeroKat*  2: Building ...  
Teach Any Cat AeroKat* 3: Applying the Mask    • Teach Any Cat AeroKat*  3: Applying ...  
Teach Any Cat AeroKat* 4: Extending the Duration    • Teach Any Cat AeroKat*  4: Extending...  
Teach Any Cat AeroKat* 5: Inhaling the Medication    • Teach Any Cat AeroKat*  5: Inhaling ...