Yup, cut them down to a pair or two of buds - that helps most young clematis send up more stems. For future years, keep track of when they bloom to know when and how/if to prune them. Type 2 bloom in spring (usually May here) and may benefit from a light pruning right after bloom. They may bloom again in the fall. Type 3 bloom in summer and benefit from a hard pruning in winter-early spring annually.

Thanks for responding. You're always so helpful. I have a spring blooming clematis I cut down to the ground in the fall. This will be year 3. Will it stunt it's growth being that I cut it down?

Pruning won't stunt its growth, it will just delay bloom a bit. Here I often find that type 2 prune (spring bloomers other than C. montana and those from the Atragene group that are both type 1, little to no prune) will die back to the snow line - not always, but often. So mother nature prunes them back, but they still grow and bloom, just a bit later. In Chicago the same thing may happen some years, especially those where the lake freezes and it's colder without the water's moderating effect like it was 2? winters ago. It does mean that in die-back years that the type 2 double flowered plants won't have double blooms since the doubles form on the previous year's wood while the singles form on the new growth for most of those. So for instance I grow 'Piilu and 'Daniel Dondera' and have never seen a double flower on either one, but still like them both - I actually prefer singles.