...years and years ago (when I was 15) when I used to bite my nails the way I stoped was to just bite on my thumb nails, I let the others grow, manacured them and had nail varnish on every day ...they looked fab and my thumb nails were horrid..but still I could not stop my habbit...so I grew one thumb nail and eventually weaned myself off chewing the last one as it just looked awful compared to the rest of my lovely nails which were eventually all about 1- 1.5 inches long, then by the age of 18 I was in the real world where I had to work for a living , not to mention housework, since then my nails just break and are quite short...but I never went back to chewing.... ( though I do hack at my toenails!!!!...can't believe I just admited to that)...