The Frost Giants were around before the Aesir or Vanir. They are formidable foes of Asgard, so they are more intelligent than Trolls. Some of them are helpful, or even friendly, but some are vicious and mean, spiteful.
Features to include when drawing:
- Pasty white or white skin color
- Eyes black, yellow, or white
- Hair is optional – but if they have hair, it is black, white, or blue
- Facial hair optional
- About the same size as the ancestors
- Muscular like the ancestors
- They are formidable foes, so not dumb looking
- Weaponry of any kind, but make the weapons look different than those of the ancestors
- Foes of Asgard, so the Frost Giants depicted should be as enemies, “bad guys”.
Don't depict them as "giants" literally, or gigantic, but roughly the same size as the Gods. Think larger than life, leader/king of a realm or kingdom.
The mythological depiction is a metaphor for reputation, symbolism, and/or what they are known for.