Also the design of pillars have to keep up with the time. Far gone are the days when we mappers have been proud of creating a round pillar with 12 or 16 vertices and non-aligned STARTAN textures. Today's pillars have to be outrageous regarding quality, detail and also scale.

The room in shot number one isn't that interesting at all. Just take a look at the plain usage of one single texture, the few crates, the enemies and the light sources. Normally, no one would ever talk about this room but fortunately, I forgot to mention the huge TEKWALL4 pillars (also with border as you can see to make the connection between pillar and room better). In a small room like the E1M1 startroom, such a pillar would look totally deplaced but a very large room, you need large and impressive columns like this one in TNT:LE. (buildtime 15-20 minutes)

Summary: The great thing about pillars is the same as with lights: As long as you have enough space, you can place them wherever you want. Also, you can vary their design in every single small aspect from smart & slim columns to huge and impressive (in scale) pillars, carrying a weight of hundreds of tons. Just be creative and try what can be done :) Just as with lights!
Extra-Buildtime: "5 - 10 minutes" (depends on complexity, can be copied and pasted)
Build-Difficulty: "Low - Medium"