First of all, I have to say that I do not like the term Dwarf or Elf. Instead, the generic term for the dwarves would be Duwergan and the generic term for Elves will be Ilosian. There will be various other names for different ethnicities within these two species.
Two rather strange ideas came to mind – one about each species.
The Duwegan are basically an underground species. They dig tunnels, they are great miners and great blacksmiths. In a real sense, they are truly people of the earth. I got to thinking that a culture prone to be underground would have evolved a diet quite different than humans or any other above-ground species. Sure, they would have vegetables and protien sources. They’d have fat and oil sources as well. However, they would not necessarily have had grains or dairy. Considering that two major food groups were unavailble to them, I thought the Duwegan that first contacted humans (or any other sentient species) would be fascinated by simple things like bread and cheese.
For some reason, that seemed like a great disadvantage, so I thought about them having some sort of weird grain that grew underground. In exploring that idea, however, I couldn’t find a satisfactory grain plant. Then it occured to me that potatoes and cassava would be natural starches that they could grow. That would mean that they’d have their own version of bread and all sorts of things (potato bread), but it left out dairy. Dairy is almost entirely derived from animal milk and I wasn’t sure what could be done. So what I decided to do was make the Duwegan skilled cheesemakers, but that the cheese they make is quite rare and difficult to make. Think about how much milk a burrowing animal produces (as opposed to a cow or goat) and you can see where I’m going with this.
In order to prevent any species from suffering from a marked stereotype, this is an uncommon talent, but one that would provide some diversity to the Duwegan. I figured that ‘a duergar cheese’ would be a common phrase to mean something that was very good and very rare.
As far as the Ilosians are concerned, the idea about them was a bit different. Basically, in a world where part of every continent has areas where magic does not work and all Ilosians have a life-force type connection with the power of magic, I could not imagine them simply confining themselves to magic-enabled lands. Some uncontent Ilosian had to look at their lot in life and try to figure out a way for him or her to survive in a non-magic land.
That’s when it occured to me. Since magic is enabled by a crystalline type substance (adamite) , an Ilosian may be able to ingest this substance to maintain their ‘connection’ with the force of magic. But I wasn’t satisfied that they would have to carry a ton of magic with him/her in order to visit a non-magic area for a day or two. Then it occurred to me that if their internal physiology was different, maybe they wouldn’t have to.
Assuming that Ilosians were somehow evolved from birds, they would have a type of gizzard that would help break down food (instead of powerful acids like the human body produces). Thinking this way, an Ilosian could swallow a small pebble into their gizzard that would last quite awhile and also help them break down their food. This seemed to make the most sense.
Anywho, those are my ideas.