The Sons of Ivaldi are Dwarves.  Loki has them make Sif's golden threads for her hair after he cuts it off.  They also make Freyr's ship Skidbladnir and for Odin, his spear Gungnir.

Features to include when drawing:

• Pasty white skin color
• Hair is black
• Black eyes
• Black or gray hair, beards optional
• Shorter size, about 1 – 3 feet shorter than the Gods
• Their ears should be pointed (like a Vulcan from Star Trek, but not like World of Warcraft) so slightly longer and pointed at the tops (like the Light Elves)
• Ugly twisted faces
• They are commonly metal workers/smiths, goldsmiths
• Stocky build
• They live in caves
• Weaponry can be metalworking hammers, and depicted with bellows, an anvil, and around a hearth
• Greedy look on faces