This episode gives us our only glimpse, sadly, of moving images from what is a very impressive looking story. The long location shoot to the hills of Wales (being from Canada, and so near the Rocky Mountains, I hesitate to call anything under 2000 feet tall a "mountain") shows immediate and obvious dividends. Only the absence of snow that the production team hoped for and expected for the shoot serves to dispel the illusion of it being the Himalayas, but the well placed windy sound effects build the illusion back up.
Sound plays a big part in this whole story. The Abominable Snowmen is notable for being the only Doctor Who story to not have an incidental music score. This allows the sheer feeling of isolation to come through in the mountain scenes, as well as the quiet serenity of the scenes set in the monastery. When the monks start chanting in the background, it almost sends shivers up your spine.
Speaking of shivers and spines, the voice of Padmasambhava is genuinely creepy in both his harsh whisper voice (evil voice), but especially in its calm, soft voice. The voice has an ethereal, androgynous quality to it, making him (it?) one of the creepiest villains seen in the series yet. After the harsh tones of Daleks and Cybermen over the past few episodes, the smoothness of Padmasambhava stands out even more.
Slow moving though this story is right now, it's much like the actions of Buddhist monks in general - measured, deliberate, and nothing done without a good deal of forethought.