The NYC Subway system "How to paint a subway station pillar":
1. Do not under any circumstances sand down and prime the rusty pillar.
2. Do not remove flaking paint or fill holes or nicks in the pillars surface.
3. Paint the minimal amount possible, to achieve the famous mismatching different-aged paint checkerboard effect.
4. Put 'Wet Paint' sign in hard-to-see location, as in this picture—so the train driver is the only one who can see it.
5. Move on to next pillar, repeat...
