yes , large weekly water changes (keeping nitrates under 40) and plenty of high quality (species appropriate) foods.
Depending on the species water temps being proper helps...
The biggest factor in my experience is tank size as well.
large frequent WC are good for constant removal of the GH hormones present in the water. these hormones released by the fish are what cause growth stunting.
Well...I do 50% water changes and my fish don't seem to grow that fast. It also depends on what you want to grow out "fast" Clown Loaches, BGK, and sometimes Dats won't grow fast no matter how well you take care of them. They just need time.