My post yesterday spawned some excellent responses, and also some great comments. Rather than go through them all in detail I thought I'd summarise the best ideas and add my comments. Lots of them are Zak's, but that's because he's the type of person who has 50 ideas a day and 51 of them are good.
1. Never make monsters "scalable" unless they're basically humanoids with
levels like the PCs and so the PCs can tell them apart as characters.
This is spot on. Nothing makes a dragon - no, scratch that, any monster - less interesting than being able to fight it at 1st level and win. It is for this and many other reasons that 4th edition D&D wins the noisms prize for All Time Most Banalifying Game System Ever.
2. Finding an NPC cleric willing to heal you is fucking hard and generally
involves some creepy religious thing happening. Because miracles are
Yes. I indulged in some of it on this very blog, but while this sort of thing is fun to think and write about, nothing will kill a sense of mystery faster than making spells and miraculous healing something that can be bought for loose change. If you want somebody to cure your disease, let alone raise one of your comrades from the dead, there needs to be a price that isn't about money. There needs to be Zak's creepy religious thing happening or there needs to be a sacrifice of considerable time and effort and personal safety: think geas, not "it costs 200 gps".
3. Make [the players] cross a threshold (a clear in game threshold "Are you sure you
wish to travel down the secluded mountain pass") before having them
fight the fantastical.
I like this idea and it reminds me of the Wizard Knight, which, along with Jack Vance's Dying Earth and Lyonesse stories, and M. John Harrison's Viriconium cycle, is probably the key "fantastical fantasy" text. In Wolfe's cosmology there is Mythgarthr, the middle world, where humans live; Skai, Kleos, and Elysion (the realm of the Most High God) above it; and Aelfrice, Muspel and Niflheim (the realm of the Most Low God) beneath. Much of what is "magical" and "fantastical" comes from things of the other realms seeping through into Mythgarthr or people accidentally or purposefully moving from Mythgarthr into them. There is plenty of scope for a fantastical D&D campaign here, where adventurers deliberately delve into the dungeon which is really a gateway to lower realms, which follow different rules and whose inhabitants are mysterious and dangerous.
4. Recreate monsters - especially the humanoids. Keep them physically and statistically the same, but recreate their culture.
A simple one, this, and obvious, but it bears repeating. Why don't most DMs do this? Because they're lazy and unimaginative. I'd go further than -C, though, and say that recreating monsters doesn't have to mean keeping them physically the same, either. Hence stuff like this.
5. No "chain of humanoid enemies". Goblins are weird fairy tale monsters
with their own empire, gnolls are slavering barbarians, jackalmen wear
robes and know magic, crowmen are semidemonic and rare, white leopardmen
serve a Frazettastyle ice witch and bugbears and hobgoblins and
what-all are bizarre unique things you haven't met yet.
I've written about this recently anyway, but the whole goblin-hobgoblin-bugbear-troll thing is just the blandest, lamest, weakest thing ever unless you can find a way to really make it interesting.
6. The technique...of
providing no standardized monsters or magic items points the way to a
game system where the rules of the mundane are known to the players, but
the fantastic elements are an idiosyncratic revelation from game to
game. Yes, creating the fantastic is hard individual work for the DM.
But the alternative, especially with experienced games, is a group of
players who ready the oil when they see a troll, who can find out
exactly how much every gland in every dead monster corpse is worth, and
for whom the only surprise is tactical, not strategic.
This is a post in its own right, but stuff like the Forge helps with this. Yes, the names it comes up with are a bit formulaic and sometimes never work, but they provide food for thought: the beauty of it is you just keep pressing the 'space' bar, and even if you don't use the names they give you ideas.
Finally, there's something I'd like to try myself, which is to use tarot cards as a randomizing device. I'm imagining something like this: get a deck of tarot cards and assign certain abilities to each card (Death is a save versus death attack; The Lovers is a charm person attack; etc.). Then, when you have just come up with a monster, draw a card at random. Bingo: it has that ability, whatever it is. You then just have to come up with the physical expression of it.