I have a cat who is a chronic barfer, Ripley. Since my vet recommended I feed him only Pro Plan Sensitive Skin and Stomach he rarely barfs.

I also have cats who barf if they eat too fast so that could be it.

One other thought, Rumor went through a barfing stage when she was about a year old and then I noticed she was also a little constipated. I took her to the vet who said it was really bad hairballs and put her on Lax'Aire (a hairball rememdy). It did the trick.