Influenced by Zak's Two Minute Dungeon and the sort of "word-association test" results that came out of it.
Take a piece of paper and write down 100 words. Number them 00-99. (I did it on a single sheet of A4 in three columns). Which words? Any of them. I'd publish my list but the idea is that your list is your list and your results are your results. So DIY.
What I did is to start with a word influenced by something in my living room and immediately (i.e. with minimal thought) scribbled down the next word that the first word inspired and so on. Don't think about it, don't worry about the apparent usefulness or not of the word as I suspect that the more unlikely a word is to be dungeon-related, the more imaginative the results will turn out. When I didn't think up a new word straight away I just looked around for something like a colour or shape or an object and started again from that.
That done, throw d100 two or three times. Write the words down, try and link them to create a dungeon room or encounter. Job's a good 'un.
From my list the very first five test-shots came out like this.
SHIELD, CHROME(*), HEAD
(Very shiny spiked shield hanging on wall with impaled Barbarian's head. Either a red herring or a +1 shield but with some social and criminal implications as to using it in public. Magical status lost if head removed from shield).
(Vast rough cavern, large enough to create it's own micro-climate. One cliff face is carved to resemble huge lion face, slick with condensation and damp. Can be climbed to upper level, abseiled down back to cavern floor).
PLINTH, SURPRISE, RIVER
(A statue plinth where the original statue has been hacked off above the ankles and is missing. If climbed on, falls through floor, chance of falling A - into underground river below room or B - if not geographically possible into small black room which is a magical portal to position thirty feet above cold, fast-flowing underground river elsewhere in dungeon).
CATACOMBS, CORPSE-PAINT(***), BATTERY
(Vertical catacomb niches, sealed with stone slabs each painted with figure reminiscent of Scandinavian Black Metal musicians - black clothes, corpse-paint. Slabs held in place by crude electro-magnet built by Chaos Dwarves, opening one breaks circuit, all open. Undead daubed in black and white paint within)
(Half a Dragon skeleton, split neatly along length of spine. Curiosity/Red Herring - where's the other half and what happened?)
The next two failed to take-off (PRESS, BLOCK started off OK but went downhill with PINK & SILVER, whilst GLASS, BUTTON, RED summed to suggest that the dice wanted a fire alarm button but that just seemed silly and anachronistic) but then HAMMER, RIVER, GRASS sparked off the idea of a Warhammer, either magical or of great value located on a small island in the underground river mentioned above with the island formed from black rock and carpetted with black grass. Presumably guarded in some way.
My word list is a motley collection of barely-related entries but you could take your time and theme your list - so that you compile 100 words of funeral theme of 100 words of steampunk theme and go with that to create a more unified dungeon design.
(*) CHROME was a word I was thinking would be useless even as I was writing it down.
(**) I was downloading the Fable III trailers from XBLA as I did the original list.
(***) Copy of Cradle of Filth's Midian album lying on the sofa.