Broad gnome traits when i run dnd games.
Born Laughing: Gnomes arent scared or upset when born, they are delighted.
Complex Minds: Gnomes Arent just intelligent or curious or creative, their minds are naturally compartmentalized such that they can genuinely multitask. Not like humans, where some of us can go back and forth quickly between tasks without losing track. They can actually perform multiple mental tasks simultaneously without any "data loss". They can write a thesis while debating a completely unrelated topic, and they can focus on multiple senses at once, separately. They can hold complex systems in their minds at with moving parts as well.
Because of all this they are harder to trick with illussions or otherwise mentally overpower, because their mind is accustomed to running multiple process at once so that illusion or attack is only hitting one part of their active consciousness.
Descended From Natural Spirits Gnomes came into being when their gods (depending on setting) spoke to glimmering gems and crystals in the earth, and made them laugh. What came to life wasnt the physical gemstones and crystals themselves, but the animistic spirits or Wills of those places, taking humanoid shape in order to join their gods in making. Due to this odd origin, they still have a much more familial relationship with their deities. They honor them like matriarchs and patriarchs of their family, rather than truly seeing them as unknowable beings.
Wise Men Fear The Wrath of The Gentle Ones When Gnomes go to war, it is not pretty. Legends of Red Caps are mixed up with true stories of Gnomes on quests for revenge, and even more frightening are the Silent Ones. Gnomes who take vows of silence and don nearly featurless wooden masks, wearing clothes and armor made of bark and moss, and weilding weapons of knapped stone, like obsidian, they silently ambush leaders of the people who have wronged their communities, and no body is ever found. Often, the only clue left is their mask, left in a place chosen to send a message. "leave us alone. If you come for us, you will never return to your homes." One tale i had an NPC share with the PCs was of a kingdom that encroached on a gnomish forest in spite of polite warnings, and cut down a sacred tree.
One month later the king vanished and an obsidian dagger was left on his eldest child's pillow with a note. "The war is over. You lost. Do not seek another." When the new king summoned his generals for council, his runners returned with grim news. Every general in the kingdom was dead.
When the noble being warned by thst tale didnt take it seriously the PCs went to warn the Gnomes on the nearby forest that the humans were likely to invade soon. The gnomes cheerily acknowledged the news and bid the adventurers stay and eat.
When the humans marched into the forest they found no village, only trees and silence, until from seemingly every root and boulder and bramble came arrows and spells raining death, only for the revealed gnomes to disapear again a moment later and move to the path the remaining humans would take to retreat, using small critters as messengers to track the human army as it moved. After a week of trying to do anything of use and being decimated at each step, the few remaining humans surrendered and were lead from the forest by a small army of birds and other small forest creatures. (obviously the PCs were involved in defending the forest too, but a few low level PCs cannot stop an army)
I also usually base gnomes on Irish and Welsh mythohistorical writings rather than on normal dnd lore in terms of how they act.