I hated my classic racing skis when I got my first pair - it just felt as though I had no kick at all. One good exercise was scooting myself along with one foot - stand on your gliding leg and just do the kicks with one leg and no poles - this helped me to identify just where the kick started as I was always kicking off too late.

I still prefer skating, but it's quite satisfying to be able to classic ski fast too.