If you want snow to sparkle then you need to increase local contrast. The yellow filter that Juan mentions does that by affecting the blue sky reflections that all sunlit snow contains.

Another means of increasing local contrast would be to meter and open the lens one stop (after adjusting for filter factors) which would place the snow values on Zone VI and then giving the film plus one or one and one half development. Since increased development is more affective of the higher film densities (snow) the local contrast is increased.