Not what you say, but how you say it
One interesting technique I use a lot is to describe the area in a tone of voice different from how you would describe, say, walkng down a path or into a familiar tavern. For example, I will repeat myself in a low echo to reinforce the vast emptiness of a canyon or immense cargo bay. I 'whisper loudly', speaking in a raspy voice and putting my hand up in front of my face in regions of snow and high winds. This lends weight to your descriptions above and beyond the words themselves.
I also use my voice to create low, background sound effects. If the players are moving through a dungeon, a scuttering noise like a mouse in the distance or water dripping paints a visual picture that the players' minds end up filling in.
In one Traveller campaign, an NPC of the canine Vargr species guided the PCs through a forest looking for an abandoned outpost. I started to huff and sniff as I delivered the Vargr's dialog. Eventually I was shaking my head and pruning up my face as I described the long lost base. After a few minutes the players started to prune up their own faces, unconsiously acting like something stank. Suddenly one of them said outloud, "Goddamn, WHAT is that smell?!"
Up til that point, I never uttered a word about an odor. I didn't have to.
NewLifeForm
"Mostly Harmless"